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BOOKS AND CHARTS By VICTOR W. PAGE 


THE MODERN GASOLINE AUTOMOBILE. 1914 edition 
Just published. 840 pages. 575 illustrations and Eleven 
folding plates ------- - Price $2.50 

QUESTIONS AND ANSWERS, RELATING TO MODERN 
AUTOMOBILE DESIGN, CONSTRUCTION AND REPAIR. 

622 pages. 329 illustrations and 5 folding plates. Price $ 1.50 

MOTOR CYCLES, SIDE CARS AND CYCLE CARS, THEIR 
CONSTRUCTION, MANAGEMENT AND REPAIR. 592 
pages. 350 illustrations. 5 folding plates - Price $1.50 
LOCATION OF GASOLINE ENGINE TROUBLES MADE EASY. 

A chart 25x38 inches, showing all parts of a typical Four- 
Cylinder Engine of the Four-Cycle type - Price 25 cents 

MOTORCYCLE TROUBLES MADE EASY-A Chart, 22x30 

inches, showing sectional view of Twin Cylinder Gasoline 
Engine - -- -- -- -- - Price 25 cents 

Full descriptions of all the above will be found in back advertising pages 


I 









































MOTORCYCLES 

SIDECARS and CYCLECARS 
Construction, Management, Repair 


A Comprehensive, Non-Technical Treatise, Defining All 
Forms of the Lighter, Self-Propelled Vehicles, Principles 
of Operation, Construction and Practical Application 
of Components in Leading American and Foreign 
Machines. Also Complete Advice on Management, 
Maintenance and Repair of All Representative Types. 

By VICTOR W. PAGE, M.E. 

Author of “The Modem Gasoline Automobile.” 

“The Modern Gas Tractor,” “Automobile Questions and Answers,” etc. 



This Treatise contains over 350 Illustrations, for the most part re¬ 
produced from Engineering Drawings and Photographs of Actual 
Machines and Component Parts prepared by Leading Motor¬ 
cycle Manufacturers specially for this work. This is the 
most valuable series of Drawings pertaining to Motor¬ 
cycle Design and Construction ever published. 


NEW YORK 

THE NORMAN W. HENLEY PUBLISHING COMPANY 

132 Nassau Street 
1914 



























COPYRIGHTED 1014 BY 

THIS NORMAN W. HENLEY PUBLISHING COMPANY 


ALL RIGHTS RK SERVED 



FIRST IMPRESSION 


Nearly every illustration in this book has been especially made by 
the publishers; the use of any without permission is prohibited. 


COMPOSITION, ELECTROTYPING AND PRESSWOKK 
BY MACHO WAN A SLIPPER, NEW YORK, U S. A 


J'JL 161914 

vjl. H .{ 4 !* 1 ) S 4 



















PREFACE 

The growth of the motorcycle industry has been great during 
the past few years, and while it has not been as spectacular or 
imposing as that of its larger brother, the automobile business, 
it has reached proportions not generally realized except bj those 
in the trade or the veteran riders. At a conservative estimate, 
several hundred thousand motorcycles are in service in this country, 
and the demand is increasing as the advantages and economy 
of this efficient motor vehicle are being better realized. The 
design and constructional features of the various makes aie becom¬ 
ing standardized in some respects, though there is still considerable 
diversity in specific types. All follow certain rules of practice, 
however, and instructions for care and operation apply to all 

standard designs. 

The automobilist has been very fortunate in having a large 
number of books available that cover all phases of motoring for 
his instruction, and everything desired in that field of knowledge, 
from deep technical discussions to elementary expositions, have 
been offered at modest prices. The motorcyclist, at the other 
hand, who desired a general treatise or instructions on motorcycle 
construction and operation, has been forced to acquire his knowledge 
by much research and reading because the books on motorcycling 
have been in the nature of elementary pamphlets rather than works 

of any pretensions. 

The writer believes that there is a field for a comprehensive 
treatise dealing with motorcycles and allied subjects, and that 
some technical as well as practical information will not come 


9 




10 


Preface 


amiss, in view of the paucity of ,such facts relating to motorcycle, 
sidecar and cyclecar construction, operation and repair. Efforts 
have been made to discuss the salient points of representative 
domestic and foreign products and to show clearly the many 
mechanical points and distinctive constructions that abound in 
modern practice. The writer has been very fortunate in securing 
the co-operation of practically all leading manufacturers in the 
motorcycle industry, and many distinctive drawings and photo¬ 
graphs have been furnished especially for his use. 

While some technical information and data are given, the mate¬ 
rial, for the most part, is of a practical nature that can easily be 
assimilated and understood by anyone. The instructions given 
for control, maintenance and repair should be valuable for the 
novice rider, while the discussions of mechanical principles will 
undoubtedly appeal to the more experienced riders, dealers and 
others in the trade. 


July, 1914 


The Author. 


ACKNOWLEDGMENT 


The writer wishes to express his appreciation of the valuable 
assistance offered and consideration shown by the following firms, 
who had sufficient belief in the distinctiveness and practicability 
of their product to welcome the light of publicity, and who went to 
considerable expense and inconvenience to furnish complete de¬ 
tails, photographs and working drawings, showing important 
points of construction and design: 

Hendee Manufacturing Company, Springfield, Mass. 
Reading-Standard Company, Reading, Pa. 

Sterling Motor Company, Brockton, Mass. 

Harley-Davidson Motor Company, Milwaukee, Wis. 

Excelsior Motor Manufacturing and Supply Co., Chicago, Ill 
F. W. Spacke Machine Company, Indianapolis, Ind. 

New Departure Manufacturing Company, Bristol, Conn. 
Enfield Cycle Company, London, England. 

Rudge-Whit worth, Coventry, England. 

F. E. Baker, Ltd., Birmingham, England. 

Bowden Wire, Ltd., London, England. 

Brown Brothers, Ltd., London, England. 

Henderson Motorcycle Compan}^, Detroit, Mich. 

Consolidated Manufacturing Company, Toledo, Ohio. 
Joerns-Thiem Motor Company, St. Paul, Minn. 

Schickel Motor Company, Stamford, Conn. 

Triumph Cycle Company, Coventry, England. 

Bosch Magneto Company, New York City. 

Credit is also due to Motor Cycling, an English publication, 
for a number of illustrations of foreign machines and components 

11 


I 







12 


A ckn o ivied g merit 


and for complete fault-finding table included in last chapter; and 
to Motor Life , an American motoring print, for permission to re¬ 
publish an article prepared by the writer dealing with motorcycle 
troubles. Endeavor has been made to give suitable credit, either 
in the text or cut lines, for all other illustrations that were not 
made especially for this treatise. The photographs of foreign 
cyclecars and motorcycles are by M. Branger or Meurisse, of 
Paris, France, and were made especially for this work. 



CONTENTS 


CHAPTER I. 

Motorcycle Development and Design. 

Why Motorcycles are Popular—How Motorcycles Developed from tho 
Bicycle—Some Pioneer Motorcycles and Influence on Presei Design— 
Causes of Failures in Early Types—Mechanical Features of Early 
Forms—The Demand for More Power—Essential Requirements of 
Practical Motorcycles—Motorcycles of Various Types—Light Weight 
vs. Medium Weight Construction—Determining Power Needed—- 
Influence of Road Surface on Traction—How Speed Affects Power 
Needed—Effect of Air Resistance—How Gradients Affect Power Re¬ 
quired—Power in Proportion to Weight—Influence of Modern Auto¬ 
mobile Practice—The Modern Motorcycle, its Parts and the A Func¬ 
tions—General Characteristics Common to all Forms—Some Modern 
Motorcycle Designs.17-83 


CHAPTER II. 

The Motorcycle Power Plant Group. 


Tho Gasolino Engine and Auxiliary Devices—Features of tho Two Main 
Engine Types—Operating Principles of Four-cycle Engine—How 
Two-cycle Engine Works—Methods of Figuring Rated Horse-powtv— 
How Actual Horse-power is Tested—Relation of Torque to Horse¬ 
power and its Meaning—Reason for Cooling Engine—Air or Water 
Cooling—Efficiency of Air-cooled Motors—Methods of Air Cooling— 
Water Cooling Methods—Features of One-cylinder Motors—Advan¬ 
tages of Multiple Cylinder Forms—Types of Two-cylinder Power 
Plants—Four-cylinder Forms—Power Plant, Support and Location— 
Motorcycle Engine Parts and their Functions.84—141 


CHAPTER III. 

Construction and Design of Engine Parts. 

Methods of Cylinder Construction—Advantages of Detachable Heads— 
Materials Employed and Methods of Finishing—Combustion Chamber 
Design—Relation of Valve Placing to Engine Efficiency—Bore and 






14 


Contents 


Stroke Ratio—Influence of Compression on Power Developed— Offset 
Cylinders—Automatic and Mechanical Valves—Valve Design and 
Construction—How Valves are Operated—Valve Timing—Pistons and 
Rings—Wristpius and Connecting-rod Arrangements—Crankshaft 
Forms and Ply-wheels—Engine Base Design and Construction—Plain 
and Anti-friction Engine Bearings.145-214 

CHAPTER IV. 

Lubrication, Carburetion and Ignition. 

Theory o Lubrication—Forms of Lubricants—Devices for Supplying Oil— 
Sight Drip Feeds—Simple Splash System with Hand-pump—Mechan¬ 
ical Oilers—Lubricating Two-cycle Engines—Motorcycle Fuel, its 
Derivation and Use—How Fuel is Carried—Principles of Carburetion 
Outlined—What the Carburetor is For—Early Vaporizer Forms and 
their Defects—Elements of Carburetor Design—Features of Automatic 
Carburetors—Typical Motorcycle Carburetors—Foreign Carburetor 
Designs—Methods of Carburetor Adjustment—Typical Mufflers and 
How they Operate—Use and Abuse of the Muffler Cut-out Valve— 
How Compressed Gas is Ignited—Parts of Simple Battery System— 
High Tension Magneto Action—Operation of Standard High Tension 
Magneto—Magneto Driving Means—Ignition Timing—Detection of 
Faults. 215—284 


CHAPTER V. 

Power Transmission System Parts. 

Utility of Clutch Defined—Theory of Friction Clutch Action—Types of 
Clutches—Materials Employed in Clutches—Clutch Location—Typical 
Motorcycle Clutches—Why Change Speed Gearing is Desirable— 
Value of Variable Speed Gearing—Variable Speeds by Slipping Clutch 
—Change Speed Gear Location—Variable Speed Pulleys—Engine 
Shaft Gear—Countershaft Gears—Sliding Gear Type—Power Trans¬ 
mission Methods—Belt Drive Systems—Types of Belts--Standard 
Belt Forms—Advantages of Drive by Chains—Single Chain Direct 
Drive—Double Chain Drive—Types of Driving Chains—Combination 
Chain and Belt Drive—Bevel and Worm Gear Final Drive—Relation 
of Engine Power to Gear Ratio.285-371 

CHAPTER VI. 

Design and Construction of Frame Parts. 

The Motorcycle Frame Structure—Foot-boards—Rear ^Wheel Stands—■ 









Contents 


15 


Spring Forks—Spring Supported Seat-posts—Spring Frames—Saddles 
and Tandem Attachments—Coasting and Braking Hubs, Why Used— 
Requirements of Pedal Drive Mechanism—What Brakes Should Do— 
Force Needed at Brake—Principle of Brake Action—Friction Co¬ 
efficient and its Relation to Brake Design—Leading Types of Brakos— 
Operation of Typical Braking and Coasting Hub—How Rider’s Effort 
is Multiplied—Motorcycle Tires—Sidecar Advantages—Forms of 
Sidecars—Sidecar Attachment and Control—Methods of Starting 
Motorcycles—Indian Starting and Lighting System—Motorcycle Con¬ 
trol Methods—Bowden Wire Control.372-451 

CHAPTER VII. 

Constructional Features of Cyclecars. 

Advantages of Cyclecars—Influence of Motorcycle Design—Three Wheel 
or Tri-car Forms—Typical True Cyclecars—Seating Arrangements— 
Advantages of Narrow Tread—Cyclecar Chassis Design—Cyclecar 
Power Plants—Cyclecar Change Speed Gears—Power Transmission 
Methods—Steering Arrangements—Methods of Springing—Cyclecar 
Control Methods.452-494 


CHAPTER VIII, 

Motorcycle Maintenance, Operation and Repair. 

Motorcycle Equipment—Lighting Systems—Alarms, Tools and Supplies— 
Directions for Starting Motor—Instructions for Operating Motor¬ 
cycle—Advice on Lubrication—Motorcycle Troubles—Classification 
of Engine Defects—Testing Ignition Systems—Common Faults in 
Carburetion Systems—Causes of Lost Compression—Causes of Irreg¬ 
ular Motor Operation—Conditions Producing Overheating—Causes of 
Noisy Operation—Valve Removal and Grinding—Removing Carbon 
Deposits—Instructions for Running and Setting De Luxe Motors— 
Defects in Power Transmission Elements—Testing for Chain Aline- 
ment—How to Adjust Chains—Slipping Belt Drive—Care of Leather 
Belts—Care of Wheels—Common Defects in Clutches—Derangements 
in Change Speed Gearing—Adjustment of Brakes—Repairing Inner 
Tube Punctures—Outer Casing Repairs—Advice to Prospective Pur¬ 
chasers of Second-hand Motorcycles..495-541 


l 
















Motorcycles, Side Cars and Cyclecars 


CHAPTER I. 

MOTORCYCLE DEVELOPMENT AND DESIGN. 

Why Motorcycles are Popular—How Motorcycles Developed from the 
Bicycle—Some Pioneer Motorcycles and Influence on Present Design- 
Causes of Failures in Early Types—Mechanical Features of Early 
Forms—The Demand for More Power—Essential Requirements of 
Practical Motorcycles—Motorcycles of Various Types—Light-Weight 
vs. Medium-Weight Construction—Determining Power Needed—In¬ 
fluence of Road Surface on Traction—How Speed Affects power Needed 
—Effect of Air Resistance—How Gradients Affect Power Required— 
Power in Proportion to Weight—Influence of Modern Automobile Prac¬ 
tice—The Modern Motorcycle, Its Parts and Their Functions—General 
Characteristics Common to all Forms—Some Modern Motorcycle 
Designs. 

The motorcycle has been aptly termed the “poor man’s automobile” 
and to one fully familiar with self-propelled vehicles, this term is no 
misnomer. The modern machine, with its ease of control, its reli¬ 
ability, its power and speed will carry one or two passengers more 
economically than any other method of transportation. Fitted with 
a side-car attachment, it becomes a practical vehicle for general use, 
as the body may be suited for passenger or commercial service. The 
demand for motorcycles, side cars and delivery vans has created an 
industry of magnitude that furnishes a livelihood for thousands of 
skilled workmen, and unmeasurable pleasure for hundreds of thou¬ 
sands who would be deprived of the joys of motoring were it not for 
the efficiency and low cost of operation of the vehicle that carries 
them swiftly and comfortably over the highways. The development 
of the motor bicycle dates back farther than that of the motor car, 
and it was demonstrated to be a practical conveyance over three 
decades ago, though it is only within the past six or eight years that 
this single-track, motor-propelled vehicle has attracted the attention 
its merits deserve. 


17 





18 


Motorcycles , Side Cars and Cyclecars 


Why Motorcycles are Popular. —The automobile attracted the 
attention of the public for some time before the motorcycle became 
generally popular, and, as a consequence, the development of the 
larger vehicle was more rapid for a time. As the early buyers of 
motor cars were of the class to which money is no object, as long as 
personal wishes are gratified, most of the manufacturers then building 
bicycles, to whom the public naturally looked for motorcycles, devoted 
their energies and capital to the design and construction of auto¬ 
mobiles rather than motorcycles, because the proepect for immediate 
profits seemed greater in catering to the great demand that existed 
for any kind of automobile that would run at all. The development 
of the motorcycle was left to people, for the most part, without the 
requisite engineering knowledge or manufacturing facilities, so, natu¬ 
rally, the growth of the industry was of little moment until an equally 
insistent demand made itself felt for motorcycles, at which time people 
with capital began to consider the production of two-wheeled vehicles 
with favor. The demand for bicycles had been diminishing for several 
years, and the new type, with motor attached,^seemed to offer a field 
that could be cultivated to advantage. 

The evanescent popularity of the bicycle rand the rapid rise to 
almost universal use, with almost as rapid decline was construed as 
a warning to proceed slowly in buildingmotorcycles,-as many thought 
the future of the motorcycle would be doubtful and that it was merely 
a passing fad. The bicycle required the expenditure of considerable 
energy, and, while very valuable as an exerciser, it did not offer 
pleasure enough for the bulk of our population in proportion to the 
amount of effort involved in making trips really worth while. The 
application of mechanical power, however, removed that objection, so 
the only deterring factor to the ready adoption of the motor-propelled 
bicycle was a lack of confidence on the part of the public regarding its 
reliability. It was not long before the endurance and practicability 
of the motorcycle was established beyond doubt, and as soon as the 
advantages began to be given serious consideration, a healthy demand, 
which is growing in importance yearly, stimulated its development 
from a crude makeshift to a practical and safe method of personal 
transportation. 

The motorcycle and its various combinations with fore cars and 






Motorcycle Development and Design 19 

side cars appeals to a conservative element who consider the cost of 
maintenance and operation fully as much as the initial expense of 
acquiring it. The motorcycle really has many fundamental advan¬ 
tages to commend it, as it has the speed and radius of action of the 
most powerful motorcar, with a lower cost of upkeep than any other 
vehicle of equal capacity. As constructed at the present time, the 
motorcycle is not only low in first cost, but its simplicity makes it 
an ideal mount for all desiring motor transportation at the least ex¬ 
pense. The mechanism of the motorcycle, its control and repair, are 
readily understood by any person of average intelligence, and with 
the improved materials and processes employed in its manufacture, 
combined with the refinement of design and careful workmanship, a 
thoroughly practical and serviceable motor vehicle is produced which 
sells at but a slightly higher price than the first high-grade safety 
bicycles of fifteen years ago. At the present time, the motorcycle is 
not only popular for pleasure purposes, but it is applied to many in¬ 
dustrial and commercial applications that insure a degree of per¬ 
manency in popular estimation never possible with the bicycle. 

How Motorcycles Developed from Bicycles. —Many of the me¬ 
chanics who turned their attention to motorcycle construction were 
thoroughly familiar with bicycle practice of the period and, as con¬ 
siderable progress had been made in building light machines that 
possessed great strength for foot propulsion, it was but natural that 
the regular form of diamond frame bicycle should be adapted to motor 
propulsion by the attachment of a simple power plant and auxiliary 
devices. As a concession to mechanical power, various parts of the 
machine, such as the front forks, the rims and tires, and in some cases 
the frame tubes were made slightly heavier, but in essentials the first 
motorcycles to be made commercially followed bicycle practice, and 
with power plant removed, it would be difficult to tell them from the 
heavy built tourist models of pedal cycles. Naturally, the motor and 
tanks were not always disposed to the best advantage, and for con¬ 
siderable time, as the writer will show, much thought was spent in 
endeavoring to combine the widely varying principles found in bicycle 
and motorcycle practice and devise a hybrid machine composed of all 
the parts of the ordinary bicycle, with the various components of the 
gasoline or internal combustion power plant disposed about the frame 






20 


Motorcycles, Side Cars and Cyclecars 

at any point where attachment was possible. The motorcycle of the 
present day follows automobile principles and is radically different 
from its earlier prototypes in practically every respect except a general 
family resemblance owing to the use of two wheels, handle bar con¬ 
trol, pedals for starting and placing a saddle so the rider can keep his 
balance to better advantage by sitting astride as on the bicycle. 

Some Pioneer Motorcycles and Influence on Present Design. 
—As early as 1885, Gottlieb Daimler, who constructed the first prac¬ 
tical high-speed internal combustion engine, and who, for this reason, 



Fig. 1.—Early Model of the Daimler Motorcycle, the Parent of All 
Present Day Self-Propelled Vehicles. 


is known as “the Father of the Automobile/’ obtained a patent on 
a two-wheel vehicle shown at Fig. 1. This, while not beautiful in 
outline, was a practical motor-propelled conveyance, and may be 
justly regarded as the forerunner of the modern motorcycle. In fact, 
in general arrangement of parts, this pioneer design is not unlike the 
modern product. At that time, the only motor vehicles regarded as 
practical or capable of actual operation for limited distances were 
types propelled by electric or steam power, and it will thus be ap¬ 
parent that Daimler’s crude motor bicycle was not only the founda- 





































































Motorcycle Development and Design 21 

tion of the motorcycle industry but also formed a basis for the develop¬ 
ment of the automobile which, in its most successful form, employs 
the internal combustion motor as a source of power. 

After numerous designs in which single cylinder motors played a 
part, in 1889, Daimler patented a double inclined cylinder motor, the 
first multiple cylinder conception. This original form is that from 
which the modern V-engine, so widely used at the present time for 
cycle propulsion, was derived. This creation was also the first to be 
made in any considerable number and, even at this late day, some of 
the original Daimler engines are still operated. In this design, the 
cylinders were inclined but 15 degrees, and eccentric grooves turned 
in the fly-wheel face were utilized to operate the exhaust valves, in¬ 
stead of the cam motion which is now common. The cylinder was 
cooled by an enclosed fan wheel which supplied a current of air con¬ 
fined around the cylinder by a jacket, so the first practical high-speed 
internal combustion engine was cooled by air. This is the method 
used almost universally in the case of the bicycle motor, even at the 
present day. 

After a time other motors appeared, such as the De Dion mob 
tricycles, propelled by a small engine based on Daimler lines, and 
which were more reliable than the first steam coaches and much 
superior to the early electric vehicles in all important essentials such 
as radius of operation, cost, reliability and speed. To Daimler must 
also be given credit for the invention of the first practical carburetor, 
or device to produce a combustible gas from liquid fuel, also an im¬ 
portant factor in the development of the automobile. 

The first Daimler machine, which is shown at Fig. 1, with one side 
of the frame removed, was not unlike the modern loop-frame machine 
in important respects. While the wheels were placed rather close 
together, the motor placing was intelligently thought out, and was 
so installed that the center of gravity was brought closer to the 
ground than in many of the machines which succeeded it. The drive 
from the pulley on the motor crankshaft to a larger member on the 
rear wheel and the use of a jockey pulley or belt tightener to obtain 
a clutching effect has not been altered in principle since its first ap¬ 
plication by Daimler. Steering was accomplished by a steering head 
construction practically the same as on present-day machines. The 





22 Motorcycles , Sirf# Car s and Cyclecars 

early form of Daimler motor did not have very much flexibility on 
account of the sluggish action of the vaporizer and the ignition by 
hot tubes so the speed was varied largely by allowing the driving belt 
to slip and by applying the brake. This was done by a controller 
wheel carried by a standard just in front of the operator s seat. When 
this was rotated in one direction, the jockey pulley or idler was allowed 
to drop, so that the belt became loose while a spoon brake, working 
on the rear wheel tire, was applied progressively as the belt tension 
was diminished, and consequently the driving power was reduced. 



Fig. 2.—Early Daimler Motorcycle With Countershaft Drive. 

A later form of Daimler bicycle, in which a countershaft was used, 
is shown at Fig. 2. The drive from the motor crankshaft to a pulley 
comprising one member of the countershaft assembly was by belt 
while a small spur gear provided a further reduction in speed by en¬ 
gaging an internal gear attached to the rear wheel spokes. It will 
be evident that Daimler not only originated the direct drive motor¬ 
cycle but that he was also responsible for the first conception of the 
countershaft drive form. Attention is directed to the use of the 
auxiliary wheels mounted on each side of the rear driving member to 




























Motorcycle Development and Design 


23 


steady the machine and keep it upright when not in motion. The 
lines of either of the Daimler machines are not unlike the forms we 
are familiar with, and the resemblance is striking enough, so that the 
parentage of the modern motorcycle can never be questioned. Daim¬ 
ler, as well as Carl Benz, who was working on a motor-tricycle at the 
time the former brought out his engine, next directed his energies to 
the improvement and construction of motor-propelled vehicles of the 
three- and four-wheel forms instead of the two-wheeler. Although 
there were spasmodic efforts made by some engineers in motorcycle 
design, most of them confined their efforts in refining the bicycle, 
which at that time was just beginning to attract attention because 
it offered possibilities of almost universal application. 

Among the next of the pioneer motor bicycles to attract attention 
was another German make, shown at Fig. 3. This was constructed 
by Wolfmueller & Geisenhof, of Munich, Germany. In ordinary 
appearance it resembled the conventional bicycle design intended for 
the use of women though the machine had exaggerated dimensions. 
The saddle was placed low so that the rider could rest his feet on the 
ground if he desired. The power plant was a peculiar form which was 
said to develop two horse-power, and which was capable of propelling 
the 110-pound machine at speeds ranging from three to twenty-four 
miles per hour. The motor was of the two-cylinder horizontal form 
having the cylinder heads at the front of the machine while the open 
ends of the cylinders pointed to the rear. The connecting rods ex¬ 
tended to cranks attached to the rear wheel axle, and the drive was 
direct from the motor cylinders to the traction member as in loco¬ 
motive practice. Ball-bearings were used at the ends of the connect¬ 
ing rod as well as supporting bearings for the rear wheels. The fuel 
gas was obtained from a vaporizer of the surface type and the com¬ 
pressed charge was ignited by hot tubes. The cylinders were water- 
cooled and were surrounded with water jackets, and a supply of water 
for cooling the engine was carried in a peculiarly shaped tank forming 
part of the mud-guard over the traction member. The front wheel 
was used for steering and was mounted in forks in much the same 
manner as in the machines of to-day. A hand-lever actuated-spoon 
brake served to retard the speed of the vehicle when desired by fric¬ 
tional contact with the front tire. Both wheels were provided with 


Front Wheel Brahe 


24 


Motorcycles, Side Cars and Cyclecars • 



Fig. 3.—The Wolfmueller Motorcycle, an Early Form of Unconventional Design. 























































































Motorcycle Development and Design 


25 


pneumatic tires. The engine cylinders were 3yV inches in diameter 
with a stroke of 4^ inches. The driving wheel was 22 inches in 
diameter while the front wheel was 26 inches in diameter. It is 
claimed that the fuel supply was sufficient for a run of 12 hours. 

One of the earliest of the De Dion-Bouton tricycles is shown at 
Fig. 4. This had the small air-cooled motor placed back of the rear 
axle which it drove by suitable gearing. In order to obtain the 
desired speed reduction, a small spur pinion was mounted on the 
motor crankshaft which meshed with a large spur gear attached to the 
differential case. In the tricycle shown, the gasoline vapor was pro¬ 
duced by a surface carburetor, and ignition was by hot tube. The 
machine was provided with pedals and it was possible to drive the 


CowbroV Uetfers 


CarVweW 
Tube Wmtev 


ConUvn&r 



^ ... t^pbor mid 


Fig. 4—One of the First De Dion-Bouton Motor Tricycles. 











































26 Motorcycles , Side Cars and Cyclecars 

rear axle by an independent foot-actuated sprocket and chain when 
desired. This made it possible to set the tricycle in motion by pedal¬ 
ing, and was also intended to provide a means of returning home when 
the motor became inoperative, which was not an infrequent occur¬ 
rence. Owing to the limited power of the motor, which was rated at 
about horse-power,the rider often found the pedals of some benefit 
as an aid to climbing steep grades. Some of these tricycles were con¬ 
verted into four-wheelers or quadricycles, as shown at Fig. 5, by the 
addition of a fore carriage which provided accommodations for a 
passenger. A later form of motor tricycle, in which electrical ignition 



replaced the hot tube method, is shown at Fig. 6. By careful study 
of this side view and the rear end shown at Fig. 4, it will not be difficult 
to understand the construction of the earliest form of motor tricycles 
to be used successfully. 

All of the pioneer designers did not devote their attention to tri¬ 
cycle construction, as some carried on experiments with the two¬ 
wheeled forms. One of the ingenious efforts to adapt the safety 
bicycle to motorcycle service is shown at Fig. 7. The power plant, 
which included a small gasoline engine with its auxiliary devices was 
mounted on a fixed axle at the center of the rear wheel, and remained 





































27 


Motorcycle Development and Design 

stationary while the wheel revolved around it to drive the bicycle. 
Owing to the limited amount of space provided for the power plant, 
which meant that an engine of small power only could be used, this 
form of construction did not prove as practical as those in which the 
motor and its auxiliary devices were attached to the frame. 

One of the problems that confronted the pioneer designer was the 
proper location of the power plant. The diversified designs in which 
the early designers attempted to solve this problem are clearly shown 
at Fig. 8. At A, an early form of De Dion motor bicycle is shown in 



Fig. 6.—Side View of the Ariel Motor Tricycle, a Pioneer Form 

Using Electrical Ignition. 


outline, and in order to obtain a low center of gravity, the power 
plant was placed back of the seat-post tube and crank hanger while 
the crank case was attached to the rear-fork stays. In the machine 
shown at B, which was known as the “Pernoo,” the motor was placed 
on extended stays behind the rear wheels and drove that member by 
direct belt connection. Another motorcycle which was brought out 
about this time is shown at C, and was designed by a man named 
Werner. In this construction, the motor was carried on an extension 
of the front-fork crown, and the object desired by the inventor was to 
















28 Motorcycles , Side Cars and Cyclecars 

permit one to convert an ordinary bicycle into a motorcycle by the 
addition of the modified front forks to which the engine was attached. 
Power was transmitted by means of a belt from a small pulley on the 
motor crankshaft to a larger member attached to the wheel. It is 
apparent that the designer had in mind an equal distribution of the 
load on the two wheels in the construction shown at A. In both the 
forms, shown at B and C, the weight was not distributed as it should 
be, as in one case practically ail of the weight came on the rear wheels, 
which made steering difficult, while in the other, the proportion of the 
weight carried by the front wheel was productive of skidding at the 
rear end when the machine was used on wet roads. The machines 



Fig. 7—Early Motorcycle Design With Power Plant Enclosed in 

Interior of Rear Wheel. 


shown were evolved in the period ranging from 1894 to 1898, and 
were adaptations of the diamond frame safety bicycle, which at that 
time had been demonstrated to be a thoroughly practical vehicle. 

During this period, American inventors were by no means idle. In 
1898, Oscar Hedstrom, an expert constructor of light racing bicycles, 
turned his attention to the design and construction of motor-propelled 
tandems which were used in bicycle racing as pacemakers. His 
products were very successful, and their consistent performances on 
the track, as well as the speed developed, attracted the attention of 
George M. Hendee, who owned a large interest in the Springfield 

























Motorcycle Development and Design 29 



Fig. 8._Some Early Designs of Motorcycles Showing Diversity of 

Opinion Regarding Placing of Power Plant and Auxiliary 


Devices. 



















































SO Motorcycles , Side Cars and Cyclecars 

Coliseum, a very prominent bicycle race-track of the period. Mr. 
Hendee, who was engaged in building bicycles, determined that there 
would be a great future for the motorcycle if a satisfactory machine 
for roadwork could be evolved. Negotiations began between Messrs. 
Hendee and Hedstrom, and in January, 1901, Mr. Hedstrom became 
associated with the Hendee Manufacturing Company, and the de¬ 
velopment of the Indian motorcycle began. It is said that in four 
months’ time, he not only designed the model machine, but built every 
part of it with his own hands. Many of the original features incor¬ 
porated in the first Indian machine are retained in the modern forms, 
and have not been changed in principle since used on the pioneer 
creation built thirteen years ago. 

The earliest Indian motorcycle to be manufactured in quantities is 
shown at Fig. 9, with all parts clearly outlined. The general lines of 
the diamond frame bicycle were followed in this as in other early 
forms, though a decided innovation was made by placing the motor 
in the frame in such a position that it formed a continuation of the 
seat-post tube, which was attached to the top of the cylinder. The 
motor crankcase was supported by the crank hanger which was located 
at approximately the same position as in bicycles intended for foot 
propulsion. This permitted the inventor to dispose of the auxiliary 
parts of the power plant so that the bicycle lines were not interfered 
with to any extent. The gasoline tank was mounted over the rear 
wheel and was partially supported by the mud-guard, while a smaller 
container between the rear forks and the seat-post tube served as a 
reservoir for the lubricating oil used in the engine. The carburetor 
was designed by Mr. Hedstrom, and with but few changes and refine¬ 
ments in minor detail, is used to-day, and is considered to be one of 
the most efficient of the many vaporizers used on motorcycles. The 
drive from the motor crankshaft was to a large sprocket, carried by a 
countershaft extending from the crank hanger, and this, in turn, im¬ 
parted motion to a smaller sprocket which drove the rear wheel 
through the medium of a chain connection with a sprocket on the 
rear wheel hub, which was a modified form of bicycle coaster 
brake. 

Ignition w as by battery and spark coil, and control of the power 
plant was obtained by varying the time of ignition and regulating the 


Motorcycle Development and Design 


31 



& 

bi> 

• H 


The First Indian Motorcycle to be Produced in a Commercial Way. 





























































32 Motorcycles , Side Cars and Cyclecars 

supply of gas admitted to the carburetor in much the same way as on 
modern machines. 

A feature of even the earliest Indian model was ease of control, as 
while other contemporary manufacturers were producing machines 
having levers at all points of the frame, the Indian had the grip con¬ 
trol that is now famous and almost universally used in America. By 
turning the grip on the right hand side of the handle-bar in one direc¬ 
tion, it was possible to raise the exhaust valve so that the engine 
would be inoperative, while a twist in the other direction allowed the 
exhaust valve to close, thus permitting the motor to function, and a 
further movement advanced the ignition timer to speed up the engine. 
While throttle control on the early form of machine shown was by a 
small crank attached to the top frame tube near the steering head, it 
was not long before the left grip was also used in controlling the motor 
by being attached to the carburetor throttle. Owing to the excellence 
of the Hedstrom motor and carburetor, the neatness of design and the 
ease of control, the Indian motorcycle was eagerly accepted by the 
public, and the American motorcycle industry was fairly under way. 

It must not be inferred that no other successful American machines 
were built at this time because there were quite a number of practical 
motorcycles evolved by other bicycle firms. Four of the early types 
are outlined at Fig. 10, and as the general construction and location of 
parts is clearly shown it will not be necessary to describe these machines 
in detail. This applies equally as well to the types shown at Figs. 11 
and 12. A point that will strike the observant reader is the diversity 
of ideas as relates to power plant installation, as opposed to the very 
general acceptance of one method of installation at the present time. 
For instance, in the group at Fig. 10, the Thomas and Holley machines 
have the motor mounted with the cylinder center line coinciding with 
that of the seat-post tube, while the Orient and the Mitchell had the 
motor placed well forward in the frame with the cylinder inclined 
toward the steering head instead of toward the rear of the machine. 
In every case, the drive was by means of belts. In the Thomas, a 
combination steel and leather belt was used, while in the other three 
forms flat belts were employed. Two of the machines, the Mitchell 
and the Orient, did not use belt idlers or jockey pulleys, while the 
Thomas and the Holley found the idler pulley of sufficient merit to 


Motorcycle Development and Design 


33 



Fig. 10.—Examples of Early American Motorcycle Design, All of Which Were Manufactured 

Commercial Scale. 























































34 


Motorcycles , Side Cars and Cyclecars 

incorporate it in their construction. We find the same diversity of 
practice in the motorcycles shown at Fig. 11. In two of these, the 
Merkel and the Yale-California, the motors had the cylinder inclined 
toward the steering head, while the other two, the Pope-Columbia 
and the Marsh, utilized the opposite placing of the power plant. In 
the Columbia machine, the motor was carried back of the seat-post 
tube, while in the Marsh, the cylinder formed a continuation of that 
member. The general trend of former constructors to belt drive as 
opposed to the present tendency in the other direction is also clearly 
shown in this group, as but one of the machines, the Pope, utilized 
the double chain drive which is now the leading form of power trans¬ 
mission. 

At the top of Fig. 12 is depicted a machine that in many respects 
resembles the accepted types of the present day. This was designed 
by Glenn Curtiss, now a famous aviator and builder of aerial craft. 
In this, the motor was placed with the cylinder vertical instead of 
inclined as in all the other machines shown. The business-like dis¬ 
position of the auxiliaries, such as the gasoline tank, battery box, 
muffler, carburetor, the long wheel base and the general neat appear¬ 
ance of the machine are all commendable. The only thing needed to 
make this early form of machine an equal in appearance and perform¬ 
ance to those of the present day was the addition of magneto ignition. 
The Wagner machine, which is shown in the center of the plate, incor¬ 
porated for many years a distinctive form of frame construction, inas¬ 
much as a separate loop member to carry the motor was added below 
the lower frame member of the conventional diamond frame. The 
Royal machine was also distinctive owing to the ingenious manner in 
which the power plant was housed in a nest formed by four tubes 
branching from the seat-post tube to the crank hanger. The Royal 
machine was also distinctive in the system of drive employed, because, 
while practically all of the contemporary machines, with the exception 
of the Pope and Indian, utilized belt drive, this employed a counter¬ 
shaft speed reduction and chain drive to the rear wheels. Instead of 
employing a sprocket and chain reduction, as did the Pope and the 
Indian, the drive from the motor crankshaft to the countershaft and 
the main reduction in speed was through spur gearing. A single chain 
served for both motor and pedal drive, as an ingenious clutching 


ForK 


Motorcycle Development and Design 



35 


Fig. 11.—Some Early American Motorcycles Which Show a Wide Diversity of Opinion Regarding 

Essentials of Design Which are Standardized at the Present Time. 













































36 


Motorcycles , Side Cars and Cyclecars 


arrangement was provided by which the pedals could be brought into 
engagement for propelling the machine and starting the motor, and 
then the drive was taken by the same chain from the motor crank¬ 
shaft, and the pedals automatically uncoupled by an overrunning 
clutch. 

Another form of machine developed by American engineers, which 
was called the “New Era,” on account of the number of advanced 
features incorporated in its design, is shown at Fig. 13. This was one 
of the first American machines to furnish a two-speed gear as regular 
equipment, and to substitute foot-boards instead of the usual form of 
pedaling gear. As the pedals were eliminated, it was not necessary 
to supply a seat of the usual form which is needed to permit the rider 
to pedal a machine when starting, and a more comfortable form seat, 
very much of the same nature as used in agricultural machinery, was 
provided for the rider. This seat was supported by springs, and as it 
conformed to the figure it proved to be very comfortable. The motor, 
which was a single-cylinder type was placed directly under the form 
seat, and the planetary two-speed gear was located on the engine 
shaft. The high and low-speed clutches were controlled by foot levers 
conveniently disposed on the running board, while another pedal pro¬ 
vided control of the band brake acting on the rear wheel. The form 
shown was one of the earlier models in which ignition was by battery 
and coil, but other machines were made of more modern form employ¬ 
ing a magneto. The fuel tank was carried over the rear wheel, as was 
common practice on many machines of that period and the drive was 
. by single chain direct from the driving sprocket on the motor crank¬ 
shaft to a larger member on the wheel. This machine was evidently 
too far in advance for its time, as the riders did not seem to take 
kindly to its unconventional lines which forced the company manu¬ 
facturing them out of business. It is interesting to note that in this 
early form of machine, we find incorporated so many of the improve¬ 
ments and refinement usually associated only with machines of the 
present day. 

The Demand for More Power.— When the first attempts were 
made to convert the bicycle into a motorcycle by the addition of a 
power plant, it was the intention of many of the constructors of the 
early types of machines to depend to some extent upon the rider to 


Motorcycle Development and Design 


37 


Battery Bo* GasoWne TanU 


Totk traces 



Front V/Kee\ BraV^e 
Battery Bo* 


Coun tev * h *\ 
Dy’wq. C-ham 


Fig. 12.—Some Pioneer Forms of American Motorcycles That Were 
Successfully Used Under Actual Service Conditions. 
















































88 Motorcycles , Side Cars and Cyclecars 

assist the motor at times when the resistance to motion was too great 
to be overcome by the small power plant provided. In order not to 
stress the frame tubes of the usual bicycle construction too much, the 
gasoline motors employed were of extremely low power, when judged 
in the light of our present day knowledge. Many of the successful 
motors were not over 1.25 horse-power, and a machine with a power 
plant rated at 2.50 horse-power was considered to be much heavier 
and more powerful than was absolutely necessary. The method of 
figuring the horse-power required on the early machines was very 
simple, as it was assumed that if a man, who Was commonly given a 
rating of one-eighth to one-twelfth of a horse-power could propel a 
bicycle satisfactorily, and attain fair speed, that a motor of one and 
one-quarter horse-power should certainly prove sufficiently powerful 
to take the machine anywhere the rider wanted to go. Of course, it 
was not considered a serious disadvantage if one was forced to assist 
the motor up a moderate hill or over a stretch of sandy road by vigor¬ 
ous pedaling. 

It did not take the early rider or motorcycle manufacturer long to 
discover that a frame structure that was entirely suitable for a foot- 
propelled machine was not necessarily strong enough to withstand the 
vibrations imposed by mechanical power. This vibration came, not 
only from the nature of the prime mover employed but was also due, 
in a measure, to the increased speeds made possible by the application 
of mechanical energy. As it was obviously necessary to increase the 
weight and strength of the frame to take care of the added stresses, 
it was also important to augment the power proportionately. Another 
factor that made it necessary to install more powerful motors was the 
demand for speed that soon became manifest after the machines had 
been mastered by their riders. To one not accustomed to motor¬ 
cycling, a speed of 20 or 25 miles per hour was very fast, but after 
the first few rides had been taken, and the rider had confidence in his 
machine and ability to control it, many sought for machines having 
greater power, and consequently more all around ability. This de¬ 
mand was met by the manufacturers, and the horse-power of motor¬ 
cycle power plants has increased over 800 per cent., as on makes 
that formerly utilized one and a quarter to two horse-power 
motors a decade or so back, we find on the modern forms 


Motorcycle Development and Design 


39 



Fig. 13.—The New Era Motorcycle, One of the First American Touring Models to Use a Two Speed 
Gear and to Dispense With the Usual Pedaling Mechanism. A Design That Was Ahead 



















































































40 


Motorcycles , Side Cars and Cyclecars 


powerful motors which are capable of easily developing 12 to 15 
horse-power. 

Essential Requirements of Practical Motorcycles—Before 

describing the parts of motorcycles, their functions or features of con¬ 
struction, it may be well to review a few of the essentials that are 
necessary in the practical motorcycle. 

First, the machine should not only be simple and strong in con¬ 
struction but it should have a soundly designed and well-made frame¬ 
work as well as a powerful motor. The power plant should be so in¬ 
stalled that it may be easily reached for inspection and the various 
components should be so accessibly located that any of the parts 
liable to give trouble can be reached without dismantling the entire 
machine. Most designs of the present day embody this important 
requirement. 

Second, every provision should be made for the comfort and safety 
of the rider. This means that the saddle should be placed so a low 
riding position obtains in order that the rider may be able to put his 
feet on the ground to steady himself when necessary. Comfortable 
foot-rests or foot-boards should be provided in addition to the usual 
pedaling mechanism, and all the control levers should be placed con¬ 
veniently so the rider may reach them, preferably without removing 
his hands from the handle-bars. 

Third, the modern machine should be provided with wheels and 
tires of ample size, and should also include some form of spring fork 
and resilient frame construction to absorb vibration and to relieve the 
rider of all road shocks. The machine should not only be provided 
with an efficient power transmission system but should also include 
adequate brakes. 

Fourth, the weight should be so distributed that the center of 
gravity, even with the rider in position, should come as near the 
ground as possible, in order to promote stability, and the load carried 
should also be proportioned so that the traction or driving wheel will 
carry more than the front or steering wheel. The machine should also 
be fitted with some method of free engine control so that the power 
plant may be kept running even if the machine must stop as in traffic. 
While a two-speed gear or other variable speed mechanism is the most 
desirable, it is not absolutely necessary, as very good results have 


Motorcycle Development and Design 


41 


been obtained with machines having a free engine clutch or its 
mechanical equivalent. 

Fifth, the pleasure and convenience of the rider should be given 
some consideration, as, in addition to comfort and safety, it is desirable 
to make operation of the machine as simple as possible. For example, 
some form of automatic or mechanical oiling system is much to be 
preferred to the usual hit or miss oil pump system of lubrication. A 
fairly capacious fuel container should be provided in order to insure 
a reasonable touring radius. An efficient muffler should be provided 
so that the machine will be silent in operation. The machine work on 
the engine, and the fitting of the various parts, should be accurately 
done so the power plant will retain oil and the machine be a clean one 
to handle. A fairly long wheel base and large wheels are fully as 
desirable as the use of spring forks or frames to secure easy riding. 
The proportion of power to weight should be such that an actual sur¬ 
plus of power is held in reserve under normal operating conditions for 
use in any emergency. 

Practically all of the essential requirements enumerated can be 
found in modern machines, though the average purchaser would be 
guided to a large extent in selecting a mount by a number of personal 
preferences, and it cannot be expected that any one type of machine 
will satisfy all riders. 

Motorcycles of Various Types.—Three forms of power have 
been successfully adapted to vehicle propulsion, and among the many 
diversified types of automobiles we find some propelled by gasoline 
engines, while others depend upon the energy derived from a steam 
boiler or electric battery. While either of the three main forms of 
prime movers may be used in a practical way on motor cars, attempts 
that have been made by motorcycle designers to adapt steam or elec¬ 
tric power to the two-wheel vehicle have rarely met with success. The 
electric motorcycle is impractical on account of the weight of the 
storage battery necessary to produce power, and also because its 
radius of action and possible speed would be limited. Some early 
inventors adapted the electric battery to the propulsion of three- 
wheelers or tricycles, and it was not very long ago that an announce¬ 
ment was made that an electric motorcycle would soon be available. 
To date, this promise has not been realized, and it is difficult for one 


42 


Motorcycles , Side Cars and Cyclecars 


to see how electric power could be applied to advantage on a two- 
w.heeler and obtain the same desirable features that are so easily 
secured by the use of the gasoline motor. 

Some experiments were tried in this country to apply steam power 
to motorcycles, but none of these ever proceeded far beyond the ex¬ 
perimental stage. In England, however, there is a steam-propelled 
motorcycle that is not radical in appearance and which must be a 
commercial success because it is said that it has been on the market 
for three years. The drawing at Fig. 14 shows the general appearance 
of this machine which is known as “the Pearson and Cox,” presumably 
because it is made by this firm in Shortlands. Despite the unconven¬ 
tional means of propulsion, this motorcycle is not so much different 
than those we are accustomed to that it would attract attention except 
of those well versed in motorcycle construction. 

The power is supplied by a single cylinder, single-acting steam 
engine with a bore of 1^ inches and a stroke of 23^ inches. This is 
mounted in the frame back of the seat-post tube and immediately in 
front of the rear wheel. The power plant is supported by the rear 
forks. The engine is given a nominal rating of 3 horse-power, but it is 
said that the boiler has capacity enough to furnish steam pressure 
sufficiently high so the engine will generate 6.50 horse-power. The 
power is delivered to the rear wheel through the medium of a single 
roller chain which connects sprockets mounted on the engine crank¬ 
shaft and on the rear wheel hub. Owing to the fact that the steam 
power is always in reserve and that the steam engine may be put in 
motion by simply opening a throttle valve, it will be evident that no 
clutch or variable speed gear is necessary. When climbing hills, one 
merely admits more steam to the engine cylinder and its power is 
increased proportionately as the steam pressure is augmented. 

The water is converted into steam in a flash boiler which is a coil 
composed of about 65 feet of pipe heated by the burner flame. The 
boiler is called a “flash generator” because as soon as water is pumped 
into the coil by the plunger pump driven from the engine for that pur¬ 
pose, it is converted instantaneously into steam having the high 
pressure of 1,000 pounds per square inch, and a temperature o‘f 800 
deg. Fahr. As the pump that supplies the water to the flash coil 
is driven directly from the engine, the amount of water supplied and 


Motorcycle Development and Design 


43 


consequently the steam generated is proportional to the demands of 
the engine. At very low speeds, when the steam consumption is small, 
a by-pass valve opens so some of the steam passes back into the water 
tank and is condensed into water. This valve is controlled from one 
of the grips on the handle-bar. The boiler, or rather, steam generator 
is located directly under the front diagonal frame tube and is pro¬ 
tected from dirt by a liberal sized mud-guard on the front wheel. The 
whole of the diamond of the usual type camel-back frame is filled by 
the water and fuel container. In order to prevent waste of water 
which would make frequent refilling of the tank necessary, the ex¬ 
haust steam is condensed by a suitable device and is pumped back 
into the water tank where it is used over again. 



Fig. 14.—The Pearson and Cox Motorcycle. An Unconventional 
English Design Using Steam as Motive Power. 


The heat to flash the water into steam is produced by a burner 
that utilizes crude oil, the cheapest form of oil fuel. Even though 
about twice as much of the cheap fuel is needed, as the amount of 
gasoline consumed by a gas motor of similar capacity, it is claimed 
that the fuel cost per mile is less than on the internal combustion 
engine propelled forms. The operation of starting the generator is 
not unlike that of starting the familiar gasoline torch. A certain 
amount of the oil is allowed to drip into a suitable shallow pan, and 
this puddle is ignited and heats the oil contained in the vaporizing 

















































44 Motorcycles , Side Cars and Cyclecars 

coil that forms part of the burner to a high enough point to generate 
gas, at which time the main fire may be lighted 

After the burner fire has been started, a small amount of water is 
injected into the hot flash coil by an auxiliary hand water pump, and 
the requisite steam pressure is obtained for starting the engine. Of 
course, after the vehicle is once set in motion the generation of steam 
is automatic. The speed and power of the engine may be controlled 
by a simple throttle valve in the steam line between the generator 
and engine cylinder which may be operated very easily from one of 
the grips. While this machine has had some sale in England, it is 
doubtful if the ease of control and smooth operation permitted by 
steam power offers enough advantages over the gasoline motor to 
make steam power a factor in motorcycle design. There is an added 
disadvantage in connection with steam power that the average rider 
will not take kindly to, and that is the possibility of a disastrous fire 
occurring, should the fuel tank spring aleak and allow the liquid fuel 
or fumes due to its evaporation to come in contact with the naked 
flame at the generator. 

The use of the gasoline motor as a source of power for motorcycles 
is, therefore, general and it can be stated with truth that the internal 
combustion engine is really the only practical form of power plant 
for motorcycle use. The modern forms of gasoline engine are not 
only simple in construction, easy to understand, reliable and economi • 
cal, but are also flexible enough and have sufficient reserve power so 
that there really would be no advantages of moment obtained by 
using steam or electricity that would outweigh the complication, 
weight and lack of efficiency that are common attributes of either of 
these indirect systems of power generation. In a gasoline engine, the 
fuel gas is converted into power directly in the engine cylinders, where¬ 
as with a steam engine it is necessary to convert water into steam 
and direct the steam to the engine cylinder to produce the power. 
Obviously the efficiency or amount of useful power obtained by burn¬ 
ing a given quantity of fuel would be greater if it was utilized directly 
in the cylinder or by the internal combustion process than if burned 
under a steam boiler where a large part of the heat would be wasted 
in the form of exhaust gas through the boiler flues. 

While motorcycles cannot be classified into types by the form of 




45 


Motorcycle Development and Design 

power used, as is possible with automobiles, they may be grouped 
into various classes depending upon their weight, the amount of power 
provided, the type of gasoline engine used, the method of power trans¬ 
mission, or the use to which the machine is adapted. 

For example, motorcycles are constructed even at the present day 
that have engines of lower power, and which are correspondingly light 
as a result. Such machines are called “light-weights,” a typical ex¬ 
ample of which is shown at Fig. 15. A light-weight motorcycle is not 
much heavier, as far as the frame is concerned, than the usual form of 
roadster bicycle, and the power plant need not be over 2.50 horse- 



Fig. 15.—The Motosacoche. A Typical European Lightweight Type. 


power. A light-weight motorcycle provided with a two-wheeled front 
axle instead of the conventional single wheel is shown at Fig. 18. A 
tricycle of this t}q)e is intended for elderly persons, women, or young 
people who do not desire to travel at high speeds, yet who wish to 
experience the pleasures of motorcycling, with maximum safety. 
Light-weights may be of two forms, according to the type of power 
plant used. They may be either single or double cylinder and the 
gasoline engine employed may operate on either the two-cycle or four¬ 
cycle principle. The next class of machine is the medium-weight, 
while the third classification is composed of tlie powerful touring 














46 


Motorcycles, Side Cars and Cyclecars 

motorcycles which are usually termed “heavy-weights,” on account 
of the strong construction and large power plants used. 

Either the medium-weight or heavy-weight machine may be divided 
into three general groups depending upon whether the machine is used 
for pleasure, business or racing. The medium-weight machines may 
be “singles,” on account of using one-cylinder engines, or “twins” 



Fig. 16.—Lightweight European Tricycle With Motosacoche Power 

Plant. 

because two-cylinder power plants are utilized. A single may be 
either belt or chain drive, or the engine may be two-cycle or four¬ 
cycle. A heavy-weight machine may employ any one of three types 
of power plant, as some are provided with large single-cylinder motors 
while others utilize powerful two or four-cylinder power plants. Then 
again, all machines may be grouped into two general classes, “single 
geared,” if only a free engine clutch is provided, and “two speed” or 



47 


Motorcycle Development and Design 

“variable speed,” if some form of change speed mechanism, as well as 
a clutch is included in the design. It is, therefore, extremely difficult 
for one to classify motorcycles intelligently, though for the purpose of 
description they may be grouped into, the light, medium, or heavy¬ 
weight types without considering the form of power plant used, the 
method of drive or any of the individual characteristics of the various 
designs. 

Light=weight vs. Medium=\veight Construction.—Of the three 
classes, machines that might be included in the true heavy-weight 
class are so rare that there are really only two distinct types to be 
considered. Fully 90 per cent, of the motorcycles in general use may 
be grouped in either the light-weight or medium-weight classification. 
The light-weights are obtainable in various forms as we find in the 
domestic and foreign market machines that range in capacity from 
1.75 to 2.75 horse-power, some of which use single cylinder motors 
while others employ small two cylinder engines. The light-weights 
usually range between 80 pounds and 140 pounds. Practically all 
light-weight machines, even if they utilize variable speed gearing, re¬ 
tain the pedalling gear. Where the roads are good, the light-weight 
has much in its favor. In initial cost, it is comparatively inexpensive 
and is economical of maintenance on account of the large mileage 
possible on small quantities of fuel and lubricating oil. A light-weight 
machine is easy to ride, start and control in traffic. A light-weight 
machine may be carried up or down a short flight of steps into a house 
without much trouble, and in the event-of a serious breakdown the 
lighter forms may be propelled by foot power without undue exertion 
if the transmission system is thrown out of action. The light-weight 
machine, however, has the disadvantages incidental to the use of 
low-powered engines. These are lack of speed, hill climbing ability 
and lack of capacity for rough road work. The light-weight type 
appeals to people of conservative taste, or to the middle-aged and it is 
also a very suitable form of machine for those who are active and not 
very far advanced in age to start on. It is claimed by many authori¬ 
ties that motorcycle manufacturers have reached the extreme in cater¬ 
ing to the riders demanding speed and power, and it is certainly true 
that the most powerful machines are difficult to handle, and are more 
expensive to maintain than the simpler and lighter forms. • - 




48 


Motorcycles , Side Cars and Cyclecars 


The most important class of motorcycle is the medium-weight 
machine which, for the most part, is provided with engines ranging 
from 3.50 to 6 horse-power. While these machines are generally in¬ 
tended for carrying a single passenger and are not well adapted for 
the attachment of side cars or delivery vans, still they have sufficient 
power to carry a tandem attachment on fair roads, that are not too 
hilly. Of course, if fitted with a free engine clutch and two-speed 
gear, medium-weight machines may be used in connection with side 
car or delivery van work, if the gear ratio is intelligently selected. If 
not more than 4 or 5 horse-power is desired, a single-cylinder engine 



Fig. 17.—Standard 1914 Model Single Cylinder Indian Motorcycle. 


will prove very satisfactory, and while the greater part of the demand, 
at the present time, seems to be for powerful twins, it is evident to 
one who analyzes the situation carefully that there will eventually be 
a reaction in favor of the one-cylinder type on account of its economy, 
simplicity, and ease of operation. To be thoroughly practical and 
capable of surmounting difficulties ordinarily met with, the machine 
of the futui e must include a variable speed gear as well as free engine 
clutch. The single-cylinder motorcycle shown at Fig. 17 is a repre¬ 
sentative American type that is a good example of the single-cylinder 
medium-weight class. At Fig. 18 a medium-weight single-cylinder 
machine of English design with its important parts outlined is clearly 











Motorcycle Development and Design 



Fig. 18.—The Brown (English) Motorcycle With Important Parts Clearly Indicated. 






























TocA Kit. ^ otor Contro\ 


Motorcycles , Side Cars and Cyclecars 




CU M 


% 

>~S> 
<v p 

s: 

Q/ O 

S»* jX. 
* £</> 

a 


"oo 


Fig. 19.—The Brown Light Twin Motorcycle. 



























Motorcycle Development and Design 


51 


depicted. An example of the medium-weight machine with small 
twin-cylinder engine and three-speed variable gear in the rear hub is 
shown at Fig. 19. It will be observed that the American machine is 
of the chain drive type, whereas the English designs employ V-belts 
for power transmission. The medium-weight machine answers prac¬ 
tically all of the requirements of the average rider, as it is sufficiently 
fast and powerful to make it a good touring machine and its con¬ 
struction is heavy enough to enable it to withstand the stresses inci¬ 
dental to operation on rough roads. At the other hand, the medium- 
weight machine can be handled by any person of average strength, 
and very satisfactory mileage is obtained from lubricating oil, gaso¬ 
line and tires. 

In the heavy-weight classification, we have the powerful twins and 
four-cylinder machines rated at from 7 to 10 horse-power, which have 
ample capacity to handle a side car or delivery van, and which, for 
the most part, are provided with variable.speed gears, and seldom with 
single-cylinder engines. It is hard to define sharply the distinguishing 
line between the? medium and heavy-weight classes, though most me¬ 
dium-weight machines weigh less than 210 pounds, while the heavy¬ 
weight machines will vary between that minimum and a maximum of 
about 300 pounds with full equipment. A typical machine that may 
be considered as being on the border line between the heavy-weight 
and medium-weight classes is shown at Fig. 20. This is an American 
design and is fitted with a motor rated at from 7 to 9 horse-power, anti 
a variable speed gear. A machine of the true heavy-weight class 
which is equipped with a four-cylinder power plant is shown at 
Fig. 21. 

On this machine it will be noticed that the usual form of pedaling 
gear is omitted entirely, because the machine is so heavy that it would 
be practically impossible to pedal it for any distance in event of break¬ 
down of the power plant. Fortunately, the gasoline engine has been 
developed to a point where serious derangements are practically un¬ 
known, and on most of the medium-weight machines the usual pedal¬ 
ing gear is provided only to facilitate starting and to provide for 
brake operation rather than as a means of propulsion. A machine 
of the type shown at Fig. 21 is practically a two-wheeled automobile 
and demonstrates clearly how radically different the modern motor- 


52 


Motorcycles, Side Gars and Gyclecars 



X 

V 

V— 

ft) § 

ccJ 


S- 

<i> 

-J 

Q) 

o 

</) 

* <D 

tvo 


<S 

> 

a 

s: 


V 

-O 

<v 

X 

£ 


CU/£ 


u— 

<y> 

v 

a> 

c 

3 

o 

O 


Q) 

, ^ 
y- 

% 

O 

*3 

Q) 

cO 

OO 

p 

y 

V 

S3- 

if) 


Fig. 20.—The Yale Two Speed Twin Cylinder Model for 1914. 

















Motorcycle Development and Design 


53 


cycle is in construction when compared to the bicycle that formed the 
basis for the first design. 

In the various classes enumerated, one will find machines that have 
been designed for certain specific purposes, for example, at Fig. 22 
is shown a stock racer which is a type of machine that is stripped 
down to as light weight as possible, and which is geared high in 01 der 
to obtain the maximum possible speed. The dropped handle-bar 
makes it easy for the rider to assume a crouching position, which, a^ 
we shall see later, makes for minimum air resistance, whereas the 
elimination of unnecessary weight also makes possible the attaining 
of high speeds with the same amount of power as would be utilized 



Fig. 21.—-The Henderson Four Cylinder Motorcycle With Tandem 

Attachment. 


in a touring machine. Obviously a machine of this type would not 
be as comfortable for road use as the regular model, on account of the 
elimination of the spring fork, the upturned handle-bar, the mud 
guards, foot rests, and other auxiliaries which increase the comfort 
of the rider. A special form of machine which, while of unconven¬ 
tional appearance, is nevertheless practical, is depicted at Fig. 23. 
Thisis intendecMor tho useof women, as it not only has the usual form 
of open frame, but also carries the power plant far enough forward 
and has it well protected so as not to interfere with the skirts of the 
rider. The tri-car shown at Fig. 24 shows the application of the 








54 


Motorcycles , Side Cars and Cyclecars 



Fig. 22.—The Excelsior Standard Stock Racer. 


motorcycle to commercial work, and the vehicle outlined is really a 
composite form, composed of a two-wheel fore-carriage attached to 
a twin-cylinder motorcycle. This motorcycle truck weighs complete 
hut 530 pounds and will carry GOO pounds in addition to the weight 
of the driver. The application of side cars will be considered in a 



Fig. 23.—An English Open Frame Motorcycle Intended For Women’s 

Use. 






















Motorcycle Development and Design 


55 


chapter devoted to that form of construction. Summing up, it is 
apparent that no one class of motorcycle will suit everybody. A 
machine that might be eminently satisfactory to one individual might 
fail entirely in fulfilling the requirements of another. The low- 
powered motorcycle is suitable for those who do not care to travel 
fast or far and who wish an economical machine that is easily handled. 
The machine of medium weight and moderate power will suit the 
average individual who wishes a strong machine capable of keeping- 
up a good average on a long trip, and that will have power enough to 



Fig. 24.—The Harley-Davidson Motorcycle Truck, a Commercial 
Application That Has Proven Thoroughly Practical. 


climb average hills and negotiate our ordinary roads, the heavy 
powerful machine is the mount for the enthusiast or expert who has 
graduated from the light-weight or medium-weight class, and who 
does not object to weight or expense as long as his machine is capable 
of high speeds with a sufficient margin of power to surmount the 
steepest hills or negotiate the most unfavorable roads. 

Determining Power Needed. —The amount of power needed 
to propel a motorcycle depends upon a number of factors, all of 













56 


Motorcycles , Side Cars and Cyclecars 


which are variable. The chief resistance to motion of self-propelling 
vehicles, such as automobiles and motorcycles, when operated on a 
level road at low and moderate speeds consists of the rolling resistance 
at the point of contact between traction member and the ground and 
friction in driving, power-transmitting and supporting elements. At 
high speeds one must take into account the factor of air resistance, 
though at low speeds this can be neglected because of its low value. 
When a motorcycle is to be propelled up a gradient, one must take 
into consideration the added resistance due to gravity, and the amount 
of power required to drive the machine depends upon the weight of 
machine and rider, steepness of the hill and the speed it is desired to 
maintain. Obviously, when descending hills, less power is needed 
than when running up hill or on the level. It takes more power to 
drive a heavy machine than a light one, other conditions being equal. 
A smooth-running construction is easier to push than one in which 
considerable friction exists, and much more power is needed on ma¬ 
chines intended for high-speed work than on types where the operating 
speeds are moderate. No matter how powerful the power plant is, 
the only available means of determining the capacity of the vehicle 
is a consideration of the amount of push available at the contact point 
of traction member and road, so while it is imperative to supply 
enough power, it is equally important to so distribute the weight as 
to insure adequate adhesion between traction member and road sur¬ 
face and to have as efficient delivery of power from motor to rear 
wheel as possible. 

Influence of Road Surface on Traction.—The resistance offered 
by various roads depends primarily on the character of the surface, 
but it is also controlled to a limited extent by the size of wheels, char¬ 
acter of tires and speed. • The traction coefficients as given by Norris 
follow: 

On rails or plates. 5.16 pounds per ton 

Asphalt or hardwood. 12.24 pounds per ton 

Macadam. 30.60 pounds per ton 

Loose gravel.140 to 200 pounds per ton 

Sand. 400 pounds per ton 

The influence of tires provided may be summed up concisely by 







Motorcycle Development and Design 


57 


saying that the resistance of iron and solid rubber tires is approxi¬ 
mately the same, while with well-inflated pneumatic tires, it will be 
25 to 30 per cent. less. The figures given above are for pneumatic 
tires, though the amount of air pressure in the tires influences the 
traction resistance to a degree. Hard tires have much less resistance 
than softer ones. A generally accepted value for well-inflated pneu¬ 
matic tires is 50 pounds per ton on hard, level asphalt, and this is the 
basis commonly used in automobile engineering practice. A value of 
80 pounds per ton for macadam and hard dirt roads will provide a 
desirable margin, and can be followed to advantage because motor¬ 
cycle wheels are relatively small, commonly ranging from 26 to 30 
inches in diameter, with 28-inch wheels predominating. Larger diam¬ 
eter wheels, such as used on automobiles, are more capable of rolling 
over minute obstructions and bridge small hollows easily and with 
less effort than would be required of supporting members of less 
diameter. The traction resistance would, therefore, be higher with 
low wheels than high ones, if the road surfaces were not absolutely 
smooth. The total effort required to overcome traction resistance R 
may be approximated by considering the following formula, in which 
W is total weight of motorcycle and load: 


W X 80 

2,000 


= R or 


W X 4 
100 



How Speed Affects Power Needed.—The value obtained by 
formula is but one of the factors to be considered in determining the 
horse-power required, therefore it is important to consider velocity 
of cycle as well. This value is generally taken in feet per minute, so 
if V is the speed in miles per hour, then 


V X 5 ’ 28 ° = 88 V 
60 

is the speed in feet per minute, and the horse-power required to over¬ 
come traction resistance of a certain vehicle and passengers at a known 
speed may be derived by the following: 


H.P. = X 88 V X 1 /33,000. 





58 


Motorcycles , Side Cars and Cyclecars 


Consider, for example, that it is desired to approximate the power 
necessary to overcome traction resistance of a motorcycle and pas¬ 
sengers weighing 500 pounds at a speed of 40 miles per hour, and that 
air resistance is neglected for the moment. Substituting known values 
in the above formula, we have 


H.P. 

H.P. 


500 X 4 
100 


X 88 X 40 X 


1 


33,000 


or 


20 X 3,_520 , 7M0Q 
33,000 33,000 


This would indicate that the torque corresponding to 2 horse-power 
applied at point of contact of traction wheel and ground would be 
capable of driving 500 pounds at the rate of 40 miles per hour over 
smooth macadam or dirt road. Let us consider a condition where the 
road surface would offer a greater resistance to traction and yet per¬ 
mit of the same speed as previously considered, or 40 miles per hour. 
If the road surface is loose gravel, the resistance will be 200 pounds 
per ton, and the formula for traction resistance would be: 


W X 200 „ W „ 

-— K or — = K. 

2,000 10 

The complete formula, taking speed into consideration, is: 

W 1 

H.P. = — X 88 X 40 X-or 

10 33,000 

500 X 88 X 40 1,760,000 

H.P. = —i- it —— or - _ ■ _ = 5.33 H.P. 


10 X 33,000 


330,000 


As the motorcyclist would be apt to meet loose gravel or dirt, the 
amount of power needed must be figured using the unfavorable roads 
as a basis. It is not likely that the rider could negotiate a soft road 
safely at 40 miles per hour, so the amount of power obtained above is 
somewhat higher than actually needed, because the speed would be 
reduced as the traction resistance increased. It would be possible to 
run at 20 miles per hour, however, so figuring power needed on this 
basis, we have: 


W 

H.P. = — X 88 X 20 1 /33,000 = 


500 X 20 X 88 


2.09 H.P. 


10 X 33,000 










Motorcycle Development and Design 


59 


It will be seen that the reduction in vehicle speed has made it 
possible to drive the motorcycle over a gravel road at 20 miles per 
hour, with but little more power than that needed to drive it over 
a macadam road at 40 miles per hour. The factor of air resistance 
must be taken into consideration at a speed of 40 miles per hour, 
however, so the power needed to overcome air resistance must be 
added to that required for traction. 

Effect of Air Resistance.—A commonly used formula for approxi¬ 
mating power needed to overcome the air resistance at various speeds 
as given by Brooks in which V is velocity of vehicle in feet per second, 
and A the projected area of front of cycle and rider, is 


H.P. 


V^X A 
240,000' 


This formula assumes still air, so if the cycle is to be driven against 
a wind of known velocity, this should be added to the cycle velocity. 
We will assume for simplicity that the motorcycle is to attain a speed 
of 40 miles per hour in still air. This is equal to a speed of 58.6 feet 
per second. The projected area will vary with the size and position 
of the rider, and even with a large rider sitting upright on the average 
motorcycle, it is not apt to exceed 5 square feet, whereas, if the rider 
crouches along the tank or rides low, the projected area of machine 
and rider will not exceed 4 square feet. 

This was determined experimentally by photographing a standard 
machine and medium-weight rider as shown at Fig.'25, having the 
rider assume two positions. At A he is sitting in the usual road¬ 
riding posture or upright, and it is reasonable to assume that this is 
the position that offers the maximum exposed area against which air 
resistance becomes effective. The view at B shows the position 
assumed by most riders on the track, in which the operator’s body 
rests on the tank, and this may be taken as the position that offers 
a minimum exposed area to air resistance. 

As the basis for figuring is the projected area, rather than actual 
exposed area, it was possible to draw outlines corresponding to the 
two positions on squared plotting paper as at Fig. 26. The photo¬ 
graphs were of such a size that each square represents one square inch 
in area. Therefore, by counting the squares, it was not difficult to 


60 


Motorcycles , Side Cars and Cyclecars 



Fig. 25.—Showing Position of Rider For Road Work at A and When 
Minimum Air Resistance is Desired at B. 










Motorcycle Development and Design 


61 


approximate the area of the rider and machine in the two positions. 
As a check upon this simple method, the areas were computed with a 
planimeter and were found to agree very closely with the areas ob¬ 
tained by counting the squares. 

Using the Brooks formula and substituting known values, we have: 


H.P. 


58.G 3 X 5 _ 201,050 X 5 
240,000 “ 240,000 


To overcome the resistance of air at speeds of 60 miles per hour, or 
88 feet per second, with rider in crouching position, we have the 
following: 




H.P. 


88 3 X 4 
240,000 


681,472 X 4 
240,000 


11.3 H.P. 


From the example previously considered, this means that it will 
require 2.1 horse-power to overcome traction resistance of a 500-pound 
motorcycle and load at 40 miles per hour, and 4.14 horse-power to 
overcome the air resistance, this making a total of 6.24 horse-power 
to propel a 500-pound motorcycle and load on a level road at a speed 
of 40 miles per hour. If only level roads were to be considered, or 
highways having a good surface, a 7 horse-power motorcycle power 
plant would be ample for all requirements up to a speed of 40 miles 
per hour, and would carry two passengers easily under these con¬ 
ditions, if there was no loss in power transmission elements. Owing 
to this loss, the power plant should be capable of delivering that 
amount of power to the rear wheel after all losses have been deducted. 

How Gradients Affect Power Required.—A motorcycle must 
be capable of surmounting any gradient apt to be met en tour if it 
is to be considered a practical conveyance, so another item that must 
be reckoned with in determining power required is the ability to climb 
hills. The amount of power needed depends on all the factors pre¬ 
viously considered, such as condition of road surface, the speed it is 
desired to attain, weight of machine and passengers, and in addition 
one must take cognizance of the steepness or pitch of the grade. 

The ability of a motorcycle to climb hills depends upon correct 
application of power to the traction member as well as ample power 
plant capacity. An engine of relatively small power may be suitable 










62 


Motorcycles , Side Cars and Cycle cars 



to push a motorcycle up a very steep hill if the gear ratio between 
engine shaft and rear wheel is low enough; at the other hand, an 
engine of twice the power would not enable one to climb a hill if the 
gear ratio was too high. With a one-gear machine, it is necessary to 




























































































































































































































































































































































































































































Motorcycle Development and Design 63 

use a gear ratio that is a compromise between the two extremes, in 
order not to sacrifice speed too much on the level, as when the gear 
ratio is low; or hill-climbing ability, as when the ratio of drive is high. 
If a two-speed machine is used, one can have a high gear that will 
permit of any speed within the capacity of the power plant and yet 
have a gear suitable for ordinary running conditions without going 
into the low speed. The lower ratio will permit the rider to negotiate 
sand or hills at a low speed, and yet the engine can be run fast enough 
to develop its full power. 

It is necessary to exert an effective push between traction member 
and the ground equal to 1 per cent, of the total load for each 1 per 
cent, rise or pitch. For example, to climb a hill having a rise of 20 
per cent, or one foot rise for every five feet in horizontal distance, it 
will be necessary to add an effective push at traction member equal 
to 20 per cent, of the total weight to the power ordinarily required on 
the level road having the same character of road surface as the hill 
to be surmounted. 

Considerable difference of opinion obtains as to the methods of 
calculating grade percentages, and some confusion may exist in the 
mind of a non-technical reader regarding the difference between the 
percentage and angle of a grade. A diagram is given at Fig. 27, which 
shows the method in vogue graphically. If it is assumed that the base 
of the triangle represents a line 1,000 feet long, and that the first 
sloping line represents a road having a rise that brings it 50 feet above 
the starting point, this would be considered as a rise of 50 feet in 
1,000 feet or 1 to 20, and would correspond to a 5 per cent, grade. The 
rise is based on the length of the base line, not of the hypotenuse of 
the triangle, which is represented by the inclined roadway. A grade 
which represents 1.00 per cent, corresponds to an angle of but 45 
degrees, not perpendicular, as is commonly supposed. When the grade 
becomes steep enough so the angle of inclination is over 30 degrees, 
gravity overcomes traction and some positive method of drive, such 
as gear wheels running on toothed tracks, is necessary to climb 
greater gradients than 30 degrees angle. 

The following table gives the percentages and corresponding angles 
of inclination for gradients ordinarily met with, except in the very 
mountainous sections of the country: 


64 


Motorcycles , Side Cars and Cyclecars 


TABLE OF GRADIENTS. 


Gra 

Per Cent. 

de. 

Units. 

Equal to 

Angle of 

Rise or Fall in 

One Mile Feet. 

20 

1 in 5 

11 deg. 19 min. 

1,056 

17 

1 in 6 

9 deg. 26 min. 

880 

14 

1 in 7 

8 deg. 9 min. 

754 

12.5 

1 in 8 

7 deg. 8 min. 

635 

11 

1 in 9 

6 deg. 17 min. 

586 

10 

1 in 10 

5 deg. 43 min. 

528 

9 

1 in 11 

5 deg. 11 min. 

480 

8 

1 in 12 

4 deg. 46 min. 

440 

7.75 

1 in 13 

4 deg. 24 min. 

406 

7 

1 in 14 

4 deg. 5 min. 

337 

6.5 

1 in 15 

3 deg. 49 min. 

352 

6.25 

1 in 16 

3 deg. 35 min. 

330 

6 

1 in 17 

3 deg. 22 min. 

310 

5.5 

1 in 18 

3 deg. 11 min. 

293 

5 

1 in 20 

2 deg. 52 min. 

204 


We have seen that a torque or push corresponding to 7 horse-power, 
at point of contact of traction wheel and ground, would be capable of 
propelling 500 pounds at the rate of 40 miles per hour over a smooth 
dirt road not having any rise, air resistance included. At this speed, 
the 28-inch traction wheel would be making a little less than 500 
revolutions per minute. This is equal to a torque that can be easily 
obtained by the following simple formula: 

m m H. p . X 63,024 

torque or 1 — -— 

R.P.M. 

Substituting known values in above equation, we find that 
7 X 63,024 


T = 


500 


= 882.3 inch-pounds at center of wheel. 


To find torque at point of contact between rear wheel and ground, the 



















Motorcycle Development mid Design 


65 


turning moment at center of wheel must be divided by wheel radius, 
or 14, giving a value of 63 pounds push. To climb a 20 per cent, 
grade, one would need an additional effective push of 100 pounds, 
which is 20 per cent, of the total weight to be moved of 500 pounds. 
To maintain a speed of 40 miles per hour up a 20 per cent, grade, an 
engine of very high power would be needed. To illustrate, if the 
engine was running at 2,500 revolutions per minute, a ratio of 5 to 1 
would permit the rear wheel to turn 500 times per minute. From 



Fig. 27.—Diagram Showing Method of Calculating Grade Percentage. 


the data at hand, it will not be difficult to figure the motor horse¬ 
power needed. To the push of 63 pounds necessary to overcome 
traction and air resistance, an additional push of 100 pounds must be 
added. This will be a total push of 163 pounds at 14 inches radius, 
which is equivalent to 2,282 inch-pounds at wheel center. This torque 
could only be obtained by expenditure of 18.1 horse-power. Ob¬ 
viously, it would not be practical to use engines of this capacity, so 
the speed would have to be reduced when climbing any hill of magni- 

















66 


Motorcycles , Side Cars and Cyclecars 


tude to correspond to the severity of the ascent, and the gear ratio 
must be selected carefully in order to enable the engine to run suf¬ 
ficiently fast to develop its maximum horse-power. 

If the speed is reduced to 20 miles per hour, as could be easily done 
by using a slow-speed gearing giving a rear-wheel speed of half that 
needed to cover 40 miles per hour, without cutting down engine speed, 
much less power would be needed to move the same weight. At 20 
miles per hour, air resistance would be so slight it could almost be 
neglected, requiring less than 0.5 horse-power to overcome it. The 
formula for finding power necessary to overcome traction resistance 
would be: 


= — ■ ■ * - X 88V X —— 

100 33,000 

Substituting known values, we have: 

H.P. = 20 X 88 _ X 20 = - 1 H.P. 


33,000 


33,000 


This would be equal to a torque of 252 inch-pounds at wheel center 
or a push of 18 pounds at tire. Add to this 100 pounds to overcome 
resistance of gradient, and we obtain a torque of 118 pounds at 14 
inches radius, or 1,652 inch-pounds at wheel center. This torque 
could be easily delivered by a 6.5 horse-power motor, neglecting 
losses in transmission which, however, would be geared down 10 to 1 
on account of the interposition of slow speed gearing. 

If we had a machine with a gear of 5 to 1, the motor should be 
capable of delivering 6.5 horse-power to the traction wheel at a 
speed of 1,250 revolutions, instead of at 2,500 revolutions per minute 
which would call for a considerably heavier and larger power plant 
on account of the greater piston displacement necessary to develop 
the same power at the lower speed. 

Power in Proportion to Weight. —The amount of power used 
by motorcycle designers does not vary materially for similar weights 
of machine, though the amount of useful energy available for trac¬ 
tion depends on many other conditions besides nominal horse-power 
of motor. The average single-cylinder machine, equipped with a 
4 to 5 horse-power engine with full equipment of accessories, will 
weigh less than 200 pounds; this is 1 horse-power for every 40 to 50 






Motorcycle Development and Design 67 

pounds vehicle weight. Several prominent light-weight machines of 
European build have engines rated at 2J4 horse-power and weigh 
well under 100 pounds. The average twin-cylinder motorcycle, with 
high gear ratio to permit of speed, must have more engine power in 
ratio to weight than a machine intended for touring, in order that it 
may have some hill-climbing ability. The weight of a number of 
prominent twin machines as determined by the writer varies between 
250 to 300 pounds with full equipment. The engine power given by 
the makers, which is a purely nominal rating figured by the simple 
empirical formula of the S.A.E., is much under the actual capacity 
of the engine because this determination is made by using a piston 
speed constant that is much less than that possible in motorcycle 
engines. The nominal ratings vary from 7 to 9 horse-power, the 
power plant of lesser capacity being furnished for the lighter machines. 
This would make the nominal power ratio to weight about 1 horse¬ 
power for each 35 pounds motorcycle weight. The actual ratio is 
much higher than this, as engines rated at 7 to 9 horse-power have 
developed twice this in brake tests, so the true ratio of power to 
weight in twin machines of American design is about 1 horse-power 
for every 20 pounds. 

As will be apparent, the addition of one cylinder to a motorcycle 
engine will practically double its power without a corresponding in¬ 
crease in weight. The engine is no heavier, save for the added cylinder 
and its internal mechanism, and the increase in size of frame parts, 
transmission elements and tires to provide adequate resistance to the 
stresses imposed by the larger power plant does not increase the weight 
materially. The average practice seems to be to provide about 1 
nominal horse-power for each 50 pounds weight in touring motor¬ 
cycles with a gear ratio that will not permit of high speeds and 
1 nominal horse-power for each 35 pounds weight in fast, twin- 
cylinder machines. The foreign rating, because of the uniformly 
better roads in England and France, as well as general use of variable 
speed gears, is somewhat different, the average being about 1 nominal 
horse-power for each 50 pounds cycle weight. 

Influence of Modern Automobile Practice. —When the motor¬ 
cycle was first conceived, it was clearly the intention of the inventors 

follow bicycle lines in their entirety, and to change the design only 


68 


Motorcycles , Side Cars and Cyclecars 


as much as was necessary to apply the internal combustion motor 
and its auxiliary devices. The first aim was simplicity, as it was 
believed that most of the recruits to the motorcycle would come from 
the vast army of wheelmen and that, unless one conformed very 
closely to the construction with which they were all familiar, they 
would not take kindly to the power-propelled forms. This same im¬ 
pression was current among early automobile designers, and for the 
first few years motor-propelled vehicles did not differ much in appear¬ 
ance from the horse-drawn carriages of the period. It did not take 
automobile designers long to realize that the requirements of the two 
forms of conveyances were radically different, and the true develop¬ 
ment of the automobile dates back to the time when the rules of 
practice applying to animal-drawn conveyances were discarded, and 
the problem of motor vehicle design studied from an entirely new 
angle. The same is true of motorcycle development, because, while 
undoubtedly the bicycle industry contributed much to the first motor¬ 
cycle designers, there is now a tendency to depart from the rules of 
practice found desirable in bicycle construction and to base motor¬ 
cycle design upon entirely new principles which apply only to self- 
propelled vehicles. 

The modern motorcycle, therefore, may be considered more of an 
automobile than a bicycle, because in the latest forms we have prac¬ 
tically all of the features found in automobile construction. The 
motorcycle of to-day uses a free engine clutch and change speed gear¬ 
ing, a positive power transmission system and forms of power plant 
not unlike those used in automobiles. The general construction 
throughout is stronger and heavier, and larger tires are used. Spring 
forks and spring frames contribute much to the comfort of the rider, 
and are really developed from the automobile, which always has 
carried the load on resilient members, whereas the majority of bicycles 
depended solely on pneumatic tires to cushion the road shocks. The 
general rules upon which modern motorcycles are based are those of 
automobile design rather than the bicycle art, and this is the best 
. insurance of reliability and efficiency that the motorcyclist of to-day 
has. So long as the development of the motorcycle follows lines that 
have been demonstrated to be correct in automobile practice, though, 
of course, changed in detail to make them suitable for the lighter con- 


Motorcycle Development arid Design 69 



Fig. 29.—Side View of the Eagle Chain Drive Twin Cylinder Motorcycle. 


















70 


Motorcycles , Side Cars and Cyclecars 


struction, we can hope for material progress and refinement and per¬ 
haps the attainment of practical perfection. 

The Modern Motorcycle, Its Parts and Their Functions.— 

Before describing the construction or features of design of motorcycle 
components, it will be well to outline the principal parts of the motor¬ 
cycle, and describe their functions so the matter that follows will be 
intelligible to the non-mechanical reader who is not experienced with 
the motorcycle mechanism. The foundation of any form of vehicle 
must necessarily be a frame to which the various parts are attached 
and which also serves to join the front and rear wheels on which the 
weight is carried. In general aspect, the frame of the conventional 
form of motorcycle does not differ from that of the bicycle, though in 
some constructions a departure is made in utilizing springs>as a portion 
of the framework. This is true of the machine which is shown at 
Fig. 28 with all important parts clearly outlined. One important 
difference between the motorcycle frame and that of the bicycle is the 
use of heavily reinforced tubing, and a departure from the usual 
diamond frame structure. The lower diagonal bar which goes to the 
crank-hanger of the motorcycle is often in the form of a loop in which 
the motor is supported. To provide greater strength than would be 
secured by but one tube at the top of the frame, practically all motor¬ 
cycles have two tubes which extend from the steering head to the 
seat-post mast or tube. In order to obtain a low saddle position, the 
top frame tube drops appreciably at a point about one-third of its 
length away from the seat post. The space between the frame bars 
is usually occupied by fuel and oil tanks. 

Next in importance to the frame structure, which includes the 
wheels, handle bars, saddle, mud guards, luggage carrier, rear wheel 
stand and foot rests as well as the frame itself is the power plant, and 
then comes the transmission system. The power plant is composed 
of a gasoline engine and a number of auxiliary devices upon which 
its action depends. The driving system includes the clutch, the vari¬ 
able speed gearing and the method of final drive. The direction of 
t a* otorcvc e s controlled in the same manner as that of 

a bicycle as the front wheel is mounted in a fork member swiveled in 
the steering head of the frame. The fork stem is usually provided 
with ball-bearings so it will turn easily, and the long leverage ob- 


H&^c\urs 


Motorcycle Development and Design 


71 



Fig. 30.—The AMC Twin Cylinder Motorcycle With Full Equipment. 























































Spring- Casing aasotme TanK trips 


I 


72 


Motorcycles , Side Cars and Cyclecars 



























Motorcycle Development and Design 


73 


tained by the conventional handle bars insures positive control of 
the front wheel under any road condition. In order to make for easier 
riding, the front wheel is carried in a supplementary movable fork 
member which is attached to links extending from the fixed fork at 
its lower end and to a laminated leaf spring at its upper end. The 
base portion of the spring is securely attached to the fixed fork 
member so that while the front wheel is free to move up and down 
under the influence of road irregularities, the main stress is taken by 
the fixed fork member which is capable of only the oscillating motion 
necessary to steer. The rear end of the frame of the machine shown 



Fig. 32.—The Schickel Motorcycle is a Distinctive Design Employing 

a Two-Cycle Power Plant. 


at Fig. 28 is also carried by a leaf spring and the rear wheel is mounted 
in a movable fork member that operates in just the same way as that 
at the front end. 

The power of practically all motorcycles is derived from burning 
gasoline vapor in the cylinders of a small heat engine which is termed 
a gasoline motor on account of having been designed primarily for 
use with that fuel, though at the present time these engines will work 
on practically any hydrocarbon liquid. Grouped with the motor are 
the auxiliary devices consisting of a carburetor to supply the explosive 
vapor to the cylinders and a magneto which furnishes the electrical 
energy used for exploding the gas in the combustion chambers. The 








74 Motorcycles , Side Cars and Cyclecars 

fuel tank, oil pump, and oil tank may also be considered part of the 
power plant. In the machine shown, the power of the engine is 
delivered from a small sprocket on the motor crankshaft to a large 
sprocket forming a part of a clutch casing. The driven members of 
the clutch are attached to a small sprocket, which in turn delivers 
its power to a larger member attached to the rear-wheel hub. The 
clutch is a simple device used to disconnect or connect the engine 
power to the rear wheel at the will of the rider. If the clutch is out, 
the engine will operate without moving the rear wheel, though if the 
clutch parts are in engagement the power will be delivered from the 
engine crankshaft to the rear wheel, and the engine cannot operate 
without producing a forward motion of the machine to which it is 
attached. The wheels used on a motorcycle resemble very much, in 
general appearance, those commonly employed on bicycles. The 
rims are heavier and made of steel, while the spokes are of much 
greater strength to sustain the greater load. The tires are of the 
double-tube fonn universally used in automobile and motorcycle prac¬ 
tice in which the inner air tube of very flexible rubber is protected 
from abrasion and depreciation incidental to road contact by a 
tougher, stronger, but less resilient casing or shoe. The general ap¬ 
pearance of motorcycles of various designs and the relation of im¬ 
portant components to each other will be readily ascertained by 
careful examination of the illustrations Figs. 28 to 39, inclusive. 

General Characteristics Common to all Forms. —While motor¬ 
cycles may differ from each other in various essentials of design, there 
are a number of characteristics which are common to all modern 
forms. Among these may be stated the method of control, the loca¬ 
tion of the power plant, the general design of the frame, the placing 
of the rider's seat, and a number of other points of likeness, which can 
be easily ascertained by inspection. The use of spring forks, and 
either spring frames or resilient saddle supports, is general, because 
the rider demands these refinements at the present time. No matter 
what form of final driving system is used, the modern machine is not 
complete without the free engine clutch or variable speed gear, and 
in most forms these two are provided in one unit. Machines that are 
built in America follow certain general features which are common 
to all, and are readily distinguishable from machines of foreign design 



Fig. 33.—Showing the Important Parts of the Triumph Single Cylinder Motorcycle, a Typical English Design, 
















































































74 


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po 

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its 

clu 

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th( 

clu 

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wit 

att 

ger 

rirr. 

gre 

doi 

ticc 

froi 

tou 

pea 

por 

car 

C 

eye 

are 

fon 

tior 

of t 

be 

eith 

the 

whs 

com 

in n 

buil 

to a 



Hafid\eW 


.Motorcycle Development and Design 


75 



Fig. 34.—Side View of Single Cylinder Motorcycle of English Design With Important Parts Marked 

For Easy Identification. 































































































76 


Motorcycles , Side Cars and Cyclecars 


which, in turn, have other peculiarities of construction which are dis¬ 
tinctive. It is the general opinion of those versed in motorcycle prac¬ 
tice that the American machine is much simpler in appearance and 
much easier to control, and withal fully as efficient as the more com¬ 
plicated foreign designs. 

Some Modern Motorcycle Designs. —The illustration at Fig. 29 

depicts a successful American motorcycle which has a particularly 
pleasing appearance. It is provided with a twin-cylinder power plant, 
and utilizes double chain drive. It incorporates the modern improve¬ 
ments such as spring forks and spring seat post, a free engine clutch, 
and handle bar control, as not only is the motor speed capable of being 
varied by the control grip, but the clutch action as well. The wheel 
base is sufficiently long to insure easy riding, the power plant is carried 
low to promote stability, and large tires make for easy riding and for 
minimum depreciation. 

The machine shown at Fig. 30 is another American design which is 
shown fully equipped with various necessary accessories. An efficient 
single cylinder machine employing a novel system of transmission is 
shown at Fig. 31. Belt drive is employed, though the arrangement of 
the under-geared clutch and drive pulley permits the use of a large 
driving member, which is much more favorable to efficient power 
transmission by belt than the smaller pulleys attached directly to the 
engine crankshaft. The machine at Fig. 32 is a distinctive American 
design employing a single-cylinder, two-cycle engine as a source of 
power. This is practically the only motorcycle on the American 
market equipped with a two-cycle power plant. There are a number 
of other distinctive features such as the spring fork construction and 
the use of a large hollow aluminum casting which not only acts as a 
fuel container but which also serves as the main member of the cycle 
frame, inasmuch as it includes the steering head at the front end and 
the seat-post supporting tube at the rear. 

The machine depicted at Fig. 33 is a representative English design 
and is a motorcycle that has received wide application abroad. If 
one compares the general construction of this design with the Ameri¬ 
can machines, it will be noted that the latter are much simpler in 
appearance, on account of concealed control members for one thing, 
and the elimination of the front rim brake and its necessary mechan- 


Motorcycle Development and Design 



77 


U- 


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CO 

t-r* 

Uj "3 

QJ 

US ^ 
+» 
+i * 


3 

P- 


o> 

o° 

<•« 

Xyo 

3 


:? 

% 










78 


Motorcycles , Side Cars and Cyclecars 





Fig. 36.—The Scott Two Cylinder Motorcycle, an English Design That Incorporates Many Distinctive 

Features. Such as a Water-Cooled Two Stroke Motor and Open Frame. 









Motorcycle Development and Design 


79 


ism, as well as a simpler design of spring fork. While the foreign 
machines are unconventional to American eyes, they are very efficient, 
and for the most part are said to be considerably more economical to 
operate than our American machines. Owing to the uniformly 
better roads found in England and France than are generally pro¬ 
vided in this country, the construction is lighter and power plants of 
lesser capacity are the rule. In the illustration at Fig. 33, all import¬ 
ant parts are clearly outlined, and from what has been presented 
previously it should not be difficult for the reader to understand their 
functions. Other representative English machines of the single¬ 
cylinder type are shown at Figs. 34 and 35. 

A machine of very unconventional appearance, yet one that should 
not be too hastily judged because of the wide variance from our pre¬ 
conceived American notions of what a motorcycle should look like, 
is shown at Fig. 36. This bristles with original features, and it has 
demonstrated its practicability beyond doubt by winning one of the 
most important of all English motorcycle competitive events, the 
Tourist Trophy race, for two years in succession. The power plant 
is a two-cylinder, two-cycle, water-cooled motor which furnishes the 
same steady pull as a four-cylinder, four-cycle with a materially 
diminished number of working parts. It is mounted on the bottom 
frame tube with the cylinders inclined toward the steering head. The 
cooling water is carried in a combined water-tank and radiator which 
is placed above and forward of the engine cylinders and just back of 
the steering head. The frame is a peculiar open girder construction, 
and it is claimed that the elimination of the top frame tube makes it 
very easy to mount or dismount from the machine. No pedals are 
provided, as the engine is started with a hand crank in the same 
manner as an automobile motor, and as a two-speed and free engine 
gear is provided, the motorcycle may be readily started from a stand¬ 
still. The fuel tank is of approximately oval section, and at the back 
end it provides a support for the rear fork stays to which the front 
end of the luggage carrier and the saddle supporting member are 
attached. The machine is provided with foot boards and a front 
wheel stand, following general European practice. One point that 
will impress the American motorcyclist is the multiplicity of control 
levers mounted on the handle bars, and the general appearance of 








80 


Motorcycles , Side Cars and Cydecars 



Fig. 37.—An Example of French Motorcycle Design. 










Motorcycle Development and Design 


81 



Fig. 38.—The Clement Twin Cylinder Motorcycle, Another Example of French Design. 






Motm'cycles , Side Cars and Cyclecars 




Fig. 39. Peugeot Twin Cylinder Model, One of the Leading French Motorcycles. 




















Motorcycle Development and Design 


83 


complication is much intensified by the number of control wires ex¬ 
tending from the handle bars to the various portions of the mechanism 
they are intended to regulate. 

The motorcycles shown at Figs. 37 to 39, inclusive, are of French 

design, and it will be apparent that these follow English practice more 

than American, though they are not as well finished in detail as either 

the English or American machines. A single-cylinder motor with a 

double chain drive is utilized for power in the motorcycle shown at 

Fig. 37, which is the simplest of the three forms. Two-cylinder motors 

are used on the remaining two designs, one using a single chain final 

drive, while the other employs a V-belt. The spring fork of the 

Clement machine, shown at Fig. 38, is of English design, though the 

similar members of the other two are undeniablv of French deriva- 

%/ 

tion. The utility of the front wheel stand which is provided on a 
number of the foreign machines is clearly outlined at Fig. 38, and it 
will be apparent that it is possible to remove both front and rear 
wheels from the machine in question without depriving it of means 
of support that will keep it upright, and in the proper position for the 
easy replacement of the wheels. This is a valuable feature, as it is 
often desirable to rotate the front wheel as when adjusting the wheel 
bearings, testing the wheel for truth of running and in making tire 
repairs. If both front and rear wheels are removed from an American 
machine, there is nothing to support the front end, and it requires 
considerable patience to find the necessary odds and ends such as 
cobbles, bricks or pieces of wood to support the motor weight by 
filling up the space between the bottom of the frame and the ground, 
in order to raise the front wheel clear for removal or to keep the frame 
in proper position for wheel replacement. In essentials, the English 
and French motorcycles do not differ from those we are familiar with, 
though, of course, one must expect to find the individuality of the 
foreign designer expressed in some ways. It is apparent to anyone 
who will consider the merits of the various designs shown, without 
prejudice, that the American designer produces neater motorcycles 
than his foreign contemporary, and machines that are really more 
practical because of the simplicity of control and the general strength 
of parts demanded by our severe operating conditions. 


CHAPTER II. 1 


MOTORCYCLE POWER PLANT GROUP. 

The Gasoline Engine and Auxiliary Devices—Features of Two Main Engine 
Types—Operating Principles of Four-Cycle Engines—How Two-Cycle 
Engine Works—Methods of Figuring Rated Horse-Power—How Actual 
Horse-Power is Tested—Relation of Torque to Horse-Power and Its 
Meaning—Reason for Cooling Engine—Air of Water Cooling—Efficiency 
of Air-Cooled Motors—Methods of Air Cooling—Water-Cooling Methods 
—Features of One-Cylinder Motors—Advantages of Multiple-Cylinder 
Forms—Types of Two-Cylinder Power Plants—Four-Cylinder Forms— 
Power Plant Support and Location—Motorcycle Engine Parts and 
Their Functions. 


The Gasoline Engine and Auxiliary Devices. —To the un¬ 
informed, a motorcycle or automobile power plant seems to consist 
essentially of a gasoline motor, but to the initiated it is known that 
while the internal combustion engine is a very important component 
of the power plant it is of little more value than so much metal when 
one of the important auxiliary devices which are distinct in construc¬ 
tion from the engine fails to function properly. A complete motor¬ 
cycle power plant with all auxiliary devices clearly outlined is illus¬ 
trated at Fig. 40, and it will be apparent that in addition to the gaso¬ 
line engine various other devices are included in the powder-producing 
assembly. 

In the first place, it is necessary to provide some method of storing 
the fuel, or a gasoline tank, and then of supplying it to the cylinder 
in the form of an inflammable gas. The latter is the function of the 
carburetor to which the gasoline from the tank is first directed. This 
device mixes the gasoline vapor and air in proper proportions, and 
supplies the vapor to the inlet valve cage of the motor. Some means 
of exploding the charge of gas in the cylinder is necessary, so an ig¬ 
nition system is used which is composed of a high-tension magneto, a 
suitable length of conductor and a spark plug in the cylinder. The 

84 


F\Wer Cap. 


Oi\ Putr^) Hat\d\e 


W\Cj\\ Tensvorv 
VJ\re To P\v)g- 

GarWelox*- 
FtoeA, Gbawber 

Fue\ Pvpe 


5pra>( V\ozx\e 


Oil Supply 

S\gV\i feed 
Gauge Glass 


0\\ P\pe Proxn 
Or\p feed. 



{\dvat\oe Lsve^ 


CoaUoI Breaker' 


Timing GearGase 


*Ve 0f*4 7 0l ' PlpeY 
"SW* RoAy 

-Oil r\pe To 
Mo\ov ’Bale 

FxWd Pipe To 
H>^\cv 

-W\ VaWe OiperaW 

£*\\a\)s\ Valve. 
^%\\a\>si Vata UJler 

T^olor Pvslon. 


Fxigixve Base 


CamOperatag Gear 


Fig. 40 .—Complete Motorcycle Power Plant, Showing the Relation of All Auxiliary Components to the Gasoline Engine. 







































































































































































































































JiCfef'y&r HptH 

vl l cT Z'uW 
— 'lote'iud’md 

-•syil lain 


-Jr.nn 
































85 


Motorcycle Power Plant Group 

wire conveys the electricity generated by the magneto to the spark 
plug inserted in the combustion chamber. In order to prevent an¬ 
noyance, due to noisy operation, a silencing device or “muffler” is 
attached at the end of the pipe through which the exhaust gases leave 
the engine cylinder. As it is important that any piece of machinery 
should be properly oiled, if it is desired that it work efficiently, a por¬ 
tion of the gasoline tank is partitioned off to form a supplementary oil 
tank to hold an adequate supply of lubricant. Some means of supply¬ 
ing the oil to the engine must be provided so, in the simple form of 
power plant outlined, one may inject the oil directly to the engine 
base through the medium of a hand-operated oil pump. This may 
be either built into or attached to the side of the tank. Another means 
of supplying oil besides the hand-pump is provided on most motor¬ 
cycle power plants, and this may be either a mechanically operated 
pump or a gravity sight-feed system in which the oil flows to the engine 
because of its weight. The amount of lubricant is regulated by a 
suitable needle valve that controls the passage leading from the oil 
tank to the gauge glass chamber. In addition to the gasoline engine 
itself, it is therefore necessary to include a carburetor or gas maker, 
a magneto or spark producer, a muffler to silence the exhaust gases, 
some system of lubrication, and suitable containers for fuel and lubri¬ 
cating oil. Another type of power plant with all parts clearly shown, 
excepting the fuel and oil containers, is presented in Fig. 41. 

Features of Two Main Engine Types. —Two types of gasoline 
engines have been applied generally to furnish power for transporta¬ 
tion purposes. These differ in construction and operating cycle to 
some extent, though in all forms power is obtained by the direct com¬ 
bustion of fuel in the cylinders of the engine. In all standard engines, 
a member known as the piston travels back and forth in the cylinder 
with what is known as a reciprocating motion, and this in turn is 
changed into a rotary motion by suitable mechanical means to be 
described fully in proper sequence. Gas engines may operate on either 
the two-cycle or four-cycle principle, the former being the simplest in 
action, though the latter is easiest to understand. 

The sectional view of a two-cycle engine depicted at Fig. 45 shows 
the three moving parts employed. The gas is introduced into the 
cylinder, and expelled from it through ports cored into the cylinder 


86 


Motorcycles, Side Cars and Cy (decars 



Fig. 41.—Complete Single Cylinder Motorcycle Power Plant of 
English Design, Showing Location of Carburetor, Magneto and 
Muffling Device. 


walls, which are covered by the piston at a certain portion of its 
travel and uncovered at other portions of the stroke. The three 
moving parts are the piston, connecting rod and crankshaft. If this 
type of power plant is compared with the four-cycle engine shown 
at Fig. 42, it will be apparent that it is much simpler in construction. 

In the four-cycle engine, the gas is admitted into the cylinder 
through a port at the head closed by a valve, while the exhaust gas 
is expelled through another port controlled in a similar manner. 












































































































Motorcycle Power Plant Group 


87 


These valves must be operated by mechanism distinct from the piston. 
In addition to the three main moving parts used in the two-cycle 
engine, there are a number of auxiliary moving members that are 
part of the valve-operating mechanism. The four-cycle engine is 
more widely used because it is the most efficient type. The two-cycle 
engine is simpler to operate and very smooth running, but it is not 
as economical as the four-cycle because a portion of the fresh gas 
taken into the cylinder is expelled through the open exhaust port with 
the burnt gases before it has a chance to ignite. As the four-cycle 
engine is more generally used, its method of operation will be described 
first. 

Operating Principles of Four=cycle Engines. —The action of 
the four-cycle type will be easily understood if one refers to the illus¬ 
trations at Figs. 42 and 43. It is called a four-stroke engine because 
the piston must make four strokes in the cylinder for each explosion 
or power impulse obtained. The principle of a gas engine is similar 
to that of a gun, i. e., power is obtained by a rapid combustion of 
some explosive or other quick-burning substance. The bullet is driven 
out of a gun barrel by the powerful gases liberated when the charge 
of powder is ignited. The piston of a gas engine is driven toward the 
open end of a cylinder by the similar expansion of gases resulting from 
combustion. 

The first operation in firing a gun or securing an explosion in the 
cylinder of a gas engine is to fill the combustion space with combust¬ 
ible material. The second operation is to compress this, and after 
compression, if the charge is ignited, the third operation of the cycle 
will be performed. In the case of the gun, the bullet will be driven 
out of the barrel, while the piston of the gas engine will be forced 
toward the open end of the cylinder. As the bullet leaves the mouth 
of the gun, the barrel is automatically cleared of the burnt powder 
gases which escape to the outer air because of their pressure. The 
gun must be thoroughly cleared before the introduction of a new 
charge of powder. In a gas engine, the fourth operation or exhaust 
stroke is performed by the return stroke of the piston. 

The parts of a simple engine have been previously indicated, and, 
in order to better understand the action, it will be well to consider 
briefly the various parts and their functions. The cylinder is an im- 


Motorcycles, Side Cars and Cyclecars 




Fig. 42.—Diagrams Illustrating Action of Four-cycle Motorcycle Power Plant. A—Piston Starting on 

Induction Stroke. B—Piston Starting on Compression Stroke. 











































Motorcycle Power Plant Group 


89 


portant member because it is in this portion that practically all the 
work is accomplished. The cylinder is provided with three ports at 
the combustion end ; one through which the gas is admitted, controlled 
by an inlet valve, another through which the burnt gas is expelled, 
closed by the exhaust valve, and the third in which the spark plug 
used to ignite the compressed gas is screwed. The reciprocating 
motion of the piston, which is the member moving up and down in 
the cylinder, is transformed into a rotary motion of the crankshaft 
by a connecting rod and crank pin. 

In the simple engine shown at Figs. 42 and 43, the inlet valve is an 
automatic one, while the exhaust member is raised from its seat by a 
mechanism including the cam-shaft, cam, valve-operating bell crank 
and plunger. At Fig. 42 -A, the piston is starting to go down on the 
first stroke of the four necessary to produce a complete cycle of opera¬ 
tions. As the piston descends, it creates a suction in the combustion 
chamber, the automatic valve is drawn down from its seat and a fresh 
charge of gas is inspired into the cylinder through the inlet pipe which 
communicates with the gas-supply device or carburetor. The inlet 
valve will remain open until the piston reaches the bottom of its 
stroke. As soon as the pressure inside the cylinder is equal to that 
outside, which condition obtains as soon as the piston has reached 
the end of its downward stroke and the cylinder is filled with gas, the 
inlet valve is closed and the piston starts to return on the next stroke, 
as shown at Fig. 42 -B. 

As both valves are closed, the combustible gas with which the 
cylinder is filled is compressed into a much smaller volume. The 
reason for compression is that any agent which gives out energy 
through the expansion of gases is rendered more efficient by confining 
it in a restricted space and directing the whole energy against some 
one spot. A tuft of guncotton could be ignited while lying loosely 
in the hand and it would burn freely but without explosion. If it is 
confined in a gun barrel and exploded, it will drive the bullet out with 
a great amount of force, or burst the metal walls of the container. 
Gasoline vapor and air will ignite and burn freely at atmospheric 
pressure, and a gasoline engine could be made to run without com¬ 
pression. The expansion of the unconfined gases would not be great 
enough to do effective work, however, and the fullest efficiency of the 


90 


Motorcycles , Side Cars and Cycle cars 



Fig. 43.—Diagrams Illustrating Action of Four-cycle Motorcycle Power Plant. C—Position of Piston at 

Start of Power Stroke. D—Piston Starting on Scavenging Stroke. 







































Motorcycle Power Plant Group 


91 


fuel is obtained by compacting it into the smallest possible space and 
then igniting it at the instant when it is compressed the most. 

Any chemical action requires close contact between the materials 
producing it, if it is to occur under the most favorable conditions. 
That which occurs when a mixture of gasoline vapor and air are 
brought into contact with the flame or arc of the electric spark is 
practically instantaneous if the gases are crowded together. If the 
gas is not properly compressed, the action becomes more dilatory, 
extending to a slow combustion wherein the temperature is not raised 
enough to expand the gases efficiently as the degree of compression 
is lessened. A good example of slow combustion is the decay of wood, 
while the phenomenon that we call “burning” may be taken as an 
illustration of quick combustion. It is said that the same amount of 
heat is produced by either combustion, but only the latter produces it 
quickly enough to be noticeable. 

The comparatively slow combustion of the gases in the engine 
cylinder, when at atmospheric pressure would not permit the energy 
derived from the heat to act all at once. When the gases are com¬ 
pressed, the particles of vapor are in such intimate contact that 
combustion is practically instantaneous, and the gases give off maxi¬ 
mum energy by expanding their utmost, due to the high temperature 
developed. The piston is also in a position to be acted upon most 
readily as the force due to pressure of the gas is directly against it 
and not exerted through a cushion of elastic half-ignited gas as would 
be the case if the charge was not compressed before ignition. 

When the piston reaches the top of its second stroke, the com¬ 
pressed gas is exploded by means of an electric spark between the 
points of the spark plug, and the piston is driven down toward the 
open end of the cylinder, as indicated at Fig. 43-C. At the end of 
this down stroke, the pressure of the gases is reduced to such a point 
that they no longer have any value in producing power. At this 
time, the cam, which is operated in timed relation to the crankshaft 
travel, raises the exhaust valve from its seat, as at Fig. 43-D, and 
the burnt gases are expelled through the open exhaust port until the 
cylinder is practically cleared of the inert products of combustion, the 
natural scavenging action, due to gas pressure, being assisted by an 
upward movement of piston. The piston once more begins to descend, 



92 Motorcycles , Side Cars and Cyclecars 

as shown at Fig. 42-A, and the inlet valve opens to admit a new 
charge. The rest of the cycle of operations follow in the order indi¬ 
cated, and are repeated as long as the cylinder is supplied with gas 
and this is ignited. 

When a two-cylinder engine is employed the action is practically 
the same, except that the two cylinders are accomplishing different 
operations of the cycle simultaneously. For example, in the engine 
shown at Fig. 44, which is of the two cylinder Y-type so widely used in 
motorcycle and cycle car practice, we find at A that while the piston 
in the left hand cylinder is going down and drawing in a charge, the 
piston in the right hand cylinder has just reached the end of its com¬ 
pression stroke, and is starting to go down under the influence of the 
expanding ignited charge of gas. When the pistons reach the bottom 
of the stroke, before starting up again it will be seen at B that the 
cylinder on the left hand side is full of fresh gas and the inlet valve is 
closed, while that on the right side is still filled with the flaming gases 
due to the previous explosion. The position of the pistons at the end 
of the next stroke is depicted at C. Here the cylinder on the left side, 
the piston of which has just compressed a charge, has its combustion 
chamber full of burning gas, while the cylinder on the right side is 
just being cleared of the inert gases produced by the previous ex¬ 
plosion through the open exhaust valve member. At D, the beginning 
of the last or exhaust stroke in the left side cylinder is indicated. As 
the piston is about to go up and the exhaust valve is opened, the burnt 
gases can be properly discharged. The right hand cylinder is filling 
with gas through the open inlet valve as the suction stroke in that 
cylinder is not yet fully completed. 

It will be evident that while the piston in one cylinder is just 
beginning to go down on an inlet stroke, that in the other cylinder is 
just completing a compression stroke. When the piston in the left- 
hand cylinder is just beginning its compression stroke, that in the 
right-hand cylinder is completing its explosion stroke. When the 
piston in the left-hand cylinder is being forced down by exploded gas, 
the similar member of the right-hand cylinder is just finishing its 
exhaust stroke. When the piston in the left-hand cylinder is starting 
on its exhaust stroke, that in the right-hand cylinder has just com¬ 
pleted its suction stroke. By having two cylinders performing differ- 


93 


Motorcycle Power Plant Group 

ent functions simultaneously, it is possible to obtain one explosion 
for each revolution of the fly-wheel, whereas in a single-cylinder 
engine it takes two revolutions of the crankshaft to obtain one useful 
power stroke. 

How Two=cycle Engine Works. —The two-cycle engine works on 
a different principle, as while only the combustion chamber end of 
the piston is employed to do useful work in the four-cycle engine, 
both upper and lower ends are called upon to perform the functions 
necessary to two-cycle engine operation. Instead of the gas being 
admitted into the cylinder, as is the case with the four-cycle engine, 
it is first drawn into the engine base, where it receives a preliminary 
compression, prior to its transfer to the working end of the cylinder. 

The views at Fig. 45 show clearly the operation of a two-port, two- 
cycle engine. Assuming that a charge of gas has just been compressed 
in the cylinder and that the upward movement of the piston while 
compressing the gas above it has drawn in a charge through the auto¬ 
matic intake valve in the crank-case, it will be apparent that as soon 
as the piston reaches the top of its stroke, and the gas has been 
properly compressed, the explosion of this charge by an electric 
spark will produce power in just the same manner as it does in the 
four-cycle motor. As the piston descends, due to the impact of the 
expanding gases, it closes the automatic inlet valve in the crank-case 
and compresses the gases confined therein. 

When the piston reaches the bottom of the cylinder it uncovers the 
exhaust port cored in the cylinder wall and the burnt gases leave the 
cylinder because of their pressure. A little further and the downward 
movement of the piston uncovers the intake port, which is joined to 
the crank-case by a by-pass passage, at which time a condition exists 
as indicated at Fig. 45, B. The piston has reached the bottom of its 
stroke, and both exhaust and inlet ports are open. The burnt gases 
are flowing out of the cylinder through the open exhaust port, while 
the fresh gases are being transferred from the crank-case, where they 
had been confined under pressure to the cylinder. The fresh gas is 
kept from passing out of the open exhaust port opposite the inlet 
opening by a deflector plate cast on the piston head, which directs 
the entering stream of fresh gas to the top of the cylinder. 

As the piston goes back on its up stroke, the exhaust and inlet ports 


94 Motorcycles , Side Cars and Cyclecars 

are closed by the piston wall, and the charge of gas is compressed 
prior to ignition. As the piston travels up on its compression stroke, 
the inlet valve in the crank-case opens, due to the suction produced 
by the piston, and admits a charge of gas through the open crank¬ 
case intake port. It will be seen that an explosion is obtained every 
two strokes of the piston instead of every four strokes, as is the case 
with a four-cycle engine. In the two-cycle form, one explosion is 
obtained for each revolution of the crankshaft, while in the four-cycle 
two revolutions of the crankshaft are necessary to obtain one power 
impulse. 

The operating principle of the three-port two-cycle engine is just 
the same as that previously described except that the gas from the 
carburetor is admitted to the crank-chamber through a small port 
in the cylinder wall, which is open when the piston reaches the top 
of the stroke. The three-port method of construction makes it 
possible to dispense with the automatic inlet valve shown in Fig. 45, 
and an engine of this kind is therefore a true valveless type. The 
two-cycle motor, while it offers many advantages in theory, has some 
weaknesses, because if it did not have any disadvantages, it would 
soon entirely supplant the more complicated four-cycle engine. The 
two-stroke type has already proven practical in the Scott motorcycle, 
a British design, and the Schickel motorcycle, an American construc¬ 
tion. At the present time, there is considerable interest manifested 
in this type of power plant in England, and a number of very efficient 
light-weight machines of two and three horse-power have been evolved 
that employ small two-cycle power plants. The only form of two- 
cycle engine to have received any application in motorcycle service 
is the valveless three-port type. The two-port system has received 
some application in marine service, but it is not capable of as high 
speed, and is not apt to function so regularly as the three-port, owing 
to check valve trouble. In the latter form, all valves are eliminated. 

As the exhaust port opens first and closes last, considerable burnt 
or inert gas will mix with and dilute each new charge, and as the 
exhaust port is still open after the inlet port closes it is apparent that 
even the best designed deflector will not provide positive insurance 
that none of the fresh charge will be discharged with the hot gas and 
escape to the outer air through the muffler without ever being exploded 


Motorcycle Power Plant Group 


95 



Fig. 45.—Diagrams Defining Action of Two-Stroke Motor. 





































































































































































Of) 


Motorcycles, Side Cars and Cyclecars 


at all. The efficiency of a two-cycle motor is considerably lower than 
that of a four-cycle, as while theoretical considerations would indicate 
that with twice the number of explosions one should double the 
power for a given cylinder volume, the actual increase over a four¬ 
cycle of the same size is but fifty per cent. Of course, the two-cycle 
engine has some real merits to offset the grave defects. Its extreme 
simplicity insures that nothing can go wrong with the engine itself 
because the piston, connecting rod and crankshaft are the sole moving 
parts. A two-cycle engine will continue to develop its rated power, 
and actually improves in power output as it continues in service. In 
a four-cycle engine, however, if the valve timing changes, as is very 
apt to occur when the valve-operating mechanism wears or gets out 
of adjustment, its efficiency is materially reduced. Barring accidents 
due to deliberate neglect, practically the only condition that can 
develop in the cylinder that will reduce the power output of a two- 
cycle engine is carbonization, and it is not a difficult matter to scrape 
off the carbon deposits from a simple cylinder with no valve chamber 
in the head, as employed in two-cycle engines. Of course, the bear¬ 
ings at the crank-case may wear to such a point that there will be 
a loss in crank-case compression, but this will not occur until the 
engine has been in service for a long period, and when bearing depre¬ 
ciation does materialize it is not a difficult proposition to refit the 
brasses, and restore the engine to its former efficiency. It is claimed 
that the two-cycle motor will not carbonize as quickly as the four¬ 
cycle because, while the latter is lubricated for the most part by hap¬ 
hazard hand pump supply, on most of the two-stroke engines lubri¬ 
cation is very easily accomplished by mixing the lubricating oil with 
the gasoline. The two-cycle construction is peculiarly well adapted 
for this system of lubrication, which would soon put a four-cycle 
engine out of commission because the fresh charge, which contains 
the oil emulsion, is first drawn into the crank-case where considerable 
of the oil will be deposited on the mechanical parts before the charge 
is directed into that portion of the cylinder above the piston. The 
two-cycle engine is not anywhere near as flexible as the four-cycle 
power plant, but it is capable of a high-power output at low speeds. 
Owing to the frequently recurring explosions an even pull or torque 
is obtained from a two-cycle motor, which promotes efficiency and 


97 


Motorcycle Power Pln?it Group 


lessens wear of the transmission system, including speed-changing 
gear as well as final drive, and which also materially augments the 
life of the tire on the traction member. 

Methods of Figuring Rated Horse=power. —To calculate the 
horse-power of any four-cycle motor, the following general formula 
may be used, this giving the output of a single cylinder, and must be 
multiplied by the number of cylinders for multiple cylinder engines: 


In which 


P L A R 
33,000 X 2 


= H.P. 


P = Pounds per square inch. 

L = Length of stroke in feet. 

A = Piston area in inches. 

R = The number of revolutions per minute. 

The following can be used for either four-cycle or two-cycle motors, 
depending on the constant used as a divisor: 

D 2 X L X n X M.E.P. XR. TIT „ 

-550^000- I H P - 4 -° yC ‘ e 

Constant for two-cycle engines, 275,000. 

D 2 = Bore of cylinders in inches squared. 

L = Stroke of piston in inches. 

R = Revolutions per minute of crankshaft. 
n = Number of cylinders. 

M.E.P. = Mean effective pressure. 

The formula below is a simple one for four-cycle engines, though 
the results can be multiplied by 1.50 to obtain power rating of 
average two-cycle engine of the same dimensions: 


H.P. = PLD 2 R with three decimal places pointed off. 

In which 

P = Mean effective pressure. 

L = Stroke in inches. 

D = Diameter in inches. 

R = Number of cylinders. 

The mean effective pressure can be assumed or taken from tables. 
A speed of 1,000 revolutions per minute is the only assumption made, 
and the formula takes into consideration pressure, bore and stroke, 




98 


Motorcycles , Side Cars and Cyclecars 

and is the simplest form to which the writer has yet been able to 
reduce the horse-power fomula, still retaining all the essentials. 

The pressure in any engine is assumed to be a mean effective 
pressure or average pressure throughout the stroke, and is written 
M.E.P. For gasoline engines of the usual four-cycle type, this pres¬ 
sure can be assumed at between 75 and 100 pounds, it, of course, 
varying with the general design. The actual mean effective pressure 



Fig. 46.—Method of Testing Power of Motorcycle Engine With 

Cradle Dynamometer. 


of an engine which has already been built can be determined by the 
manograph, which records by means of a streak of light the outline 
of the indicator card, which, if desired, can be permanently retained 
by means of a photographic plate. It can also be determined at 
speeds under 500 revolutions per minute by diagrams produced by 
ordinary steam engine indicators, but these are not accurate when 
used with high-speed gasoline engines, the manograph being far 
superior. 

Mean effective pressure increases as the compression, and decreases 
as the revolutions per minute augment. The thermal efficiency of a 
motor is the ratio between the work done and the thermal energy 
contained in the fuel consumed, and is between 15 to 30 per cent. 
The mechanical efficiency, by which is understood the ratio between 
the work actually done to the energy expended on the piston by the 
expanding gases, is approximately 85 per cent. 




































Motorcycle Power Plant Group 99 

For easy comparison of one machine with another, and for facili¬ 
tating handicapping at hill-climbs and race meets, the following 
formulae have been given out by clubs and associations. For the 
sake of uniformity, let: 

D 2 = Square of piston diameter in inches. 

L = Stroke in inches. 

R = Revolutions per minute. 

N = Number of cylinders. 

S.A.E. formula.H.P. 

Roberts formula.H.P. 

Royal Auto Club.. .H.P. 


D 2 N 

D 2 LNR 

1,800 

(D + L) 2 N 
9.92 


TABLE OF HORSE-POWER FOR USUAL SIZES OF MOTORCYCLE MOTORS, 

BASED ON S. A. E. FORMULA. 


Bore. 

Horse-power. 

Inches. 

M/M 

1 Cylinder. 

2 Cylinders. 

4 Cylinders. 

2% 

64 

2% 

5 

10 

2% 

68 

2% 

5)4 

11 

2M 

70 

3 

6 

12A 

2% 

73 

3 A 

6% 

13% 

3 

76 

3| 

7} 

141 

3J/8 

79 

ol 5 
°1 6 

7 n 

15% 

3M 

83 

4 M 

%Vi 

.... 

m 

85 

4* 


.... 


89 

4* 

n 

.... 

3% 

92 

5% 

10 % 

.... 

3M 

95 

5 % 

HM 

.... 

3Vs 

99 

6 

12 

.... 




































100 


Motorcycles , Side Cars and Cyclecars 


To simplify reading of the above, the horse-power figures are ap¬ 
proximate, but correct within one-sixteenth. 

How Actual Horse=Power is Tested. —While it is possible to 
arrive at some estimate during the preliminary designing or con¬ 
struction of a motorcycle power plant of the amount of power that 
can be expected, the only true indication of actual engine capacity 
is some form of dynamometer or brake test. A typical method of 
testing is illustrated at Fig. 46 and the general arrangement of parts 
can be readily understood by referring to the diagram. The ap¬ 
paratus used for this test is known as a “cradle-dynamometer” and 
power is measured by an electro-magnetic pull, the value of which 
increases as the engine capacity augments. The motor drives the 
armature of what is really an electric generator by a belt, and an 
electric current is produced which is dissipated or absorbed by the 
resistance Rl. This current sets up a magnetic attraction which 
tends to pull the field around with it. This field ring is not only very 
carefully balanced but is supported by ball bearings in the pedestals 
which permit it to oscillate with but slight magnetic pull. The 
amount of magnetic attraction may be measured by the weight W 
carried at the end of the long lever attached to the oscillating field. 
The pull depends upon the amount of current flowing through the 
field, and this is usually supplied from an independent source and is 
controlled by the rheostat R2. In calculating the power developed, 
it is necessary to know the number of revolutions the armature is 
making, so this is determined by the revolution counter or tachom¬ 
eter T which is driven from the armature shaft by suitable gearing 
and a flexible shaft. 

In making a test, a number of resistance coils in the rheostat Rl 
are put in circuit for absorbing the armature output, and enough 
electric current from some extraneous source is allowed to flow 
through the field by means of the rheostat R2 to hold the motor 
down to the required speed. Weights are placed on the arm at W 
until the field ring balances. The number of revolutions as indicated 
by the tachometer is noted and the horse-power obtained under these 
conditions may be readily computed. If it is desired to test the 
horse-power at lower or higher speeds, the weights are removed and 
the amount of current flowing through the field is altered to obtain 


101 


Motorcycle Power Plant Group 


the desired speed. If the current is increased the speed becomes less, 
while decreasing the current will allow the motor to run faster. When 
the proper number of revolutions are obtained, the weights are changed 
until the field ring again balances. The horse-power is very easily 
found by a simple formula which can be expressed as follows if one 
assumes that the distance from where the weight is supported to the 
center of the armature shaft is one foot: 


H.P. 


Weight X R.P.M. X 2 X 3.1416 
33,0(xT 


For example, if the motor pulls 29 pounds at 2,400 revolutions per 
minute, we would have substituting known values in the above 
formula: 


29 X 2,400 X 2 X 3.1416 
33,000 


13.25 H.P. 


If the field current is strengthened so that the motor is slowed down 
to 1,500 revolutions per minute and the torque is indicated as 36 
pounds, we have: 


36 X 1,500 X 2 X 3.1416 
33,000 


= 10. 28 H.P. 


The actual horse-power of an engine may be determined by other 
forms of dynamometers, of which the Prony brake is a widely used 
form. This differs from the electric devices described, as the power 
delivery is obtained by a friction brake that, in its simplest form, may 
consist of a rope passed around a fly-wheel or pulley attached to the 
motor shaft or driven by it and having its free ends attached to spring 
balances or one attached to a fixed point while the other is weighted. 
The usual form of Prony brake consists of a band of leather or steel 
to which a number of hardwood blocks are fastened, and the whole 
is bent around the fly-wheel of the engine to be tested to form a brake 
band, which may be made to bear against the fly-wheel with any 
degree of pressure desired by the operator. A lever is attached to 
one side of the brake hand, and the tendency of the revolving fly¬ 
wheel to carry the lever around with it when the band is tightened, 
is resisted by weights or spring balances. The method of determining 







102 


Motorcycles , Side Cars and Cyclecars 


the power with the mechanical brake is just the same as that followed 
when the electric cradle dynamometer method is employed. 

Another simple and effective method of determining the horse¬ 
power is to have the engine run a generator of electricity and absorb 
the current delivered by any suitable resistance such as banks of in¬ 
candescent lamps. The current output from the generator may be 
measured, and for every 746 watts of current obtained, the engine is 
delivering about 1.10 horse-power. While 746 watts is the electrical 
equivalent of a horse-power, there is a certain loss in energy in con¬ 
verting the mechanical power into electric current, and this must be 
considered in determining the engine power. Still another method 
of obtaining the actual horse-power of a gasoline engine is by driving 
a large air fan which has movable vanes or plates attached to the 
arms so that these may be placed at any point on the length of the 
arm. As it takes a certain amount of power to overcome air resist¬ 
ance, if the area of the plates is known, one can determine the amount 
of power delivered by the engine by considering the distance the 
blades travel in a given time. 

Relation of Torque to Horse=Power and Its Meaning.— In 

considering the power capacity of various types of prime movers, 
“torque” is a technical term that receives considerable application, 
and like most of the simple mechanical expressions, it does not mean 
much to the average reader of semi-technical or mechanical works. 
As it is a very simple way of expressing power delivered to or by a 
rotating member, such as an engine crankshaft, pulley, sprocket or 
wheel, it seems desirable that a more general understanding of this 
term should exist. The writer has used this expression previously, 
and as it will be employed in a number of the chapters to follow, in 
exposition of power generation and transmission systems, the ap¬ 
pended brief explanation may serve to promote a proper under¬ 
standing of its meaning. 

It is generally known that power is expended in doing work, and 
that as the amount of work or resistance is increased, the amount of 
power or energy required augments proportionately. The power de¬ 
livered by an engine crankshaft can be expressed very well as “torque” 
which generally is considered in pounds-inches or pounds-feet, or 
simply as a certain pull or push having a definite value in pounds. 


Motorcycle Power Plant Group 


103 


The relation between torque and horse-power is simply that the 
former is produced by or can produce the latter. The amount of 
torque is directly proportional to the power producing it, and it in¬ 
creases as the power augments, if the rotative speed remains constant. 

For example, we desire to find the useful driving force or power 
delivered by a gasoline engine of certain proportions. If the engine 
was used in motorcycle propulsion, it would be desirable to know the 
amount of pull that would be present at the pitch line of the driving 
sprocket, in order to ascertain if the engine could overcome the resist¬ 
ance of traction wheel movement. This pull would be a torque of so 
many pounds value depending upon the speed and power of the engine 
and the distance between the sprocket pitch line and a point at crank¬ 
shaft center. In ascertaining the value of the turning effort or torque, 
it is desirable to find the amount present at one inch radius from shaft 
center first, then the actual pull may be readily determined by divid¬ 
ing the torque in inch-pounds by the distance in inches from the 
crankshaft center to the point where the power is exerted. 

The following simple example will clearly define the practical ap¬ 
plication of the formula previously used to this case. The formula 
expressed as a rule is: Torque is equal to the product of the horse¬ 
power multiplied by 63,024, divided by the revolutions per minute of 
the shaft. This rule is almost universally employed in determining 
the value of the pull available from a given power at a definite point 
of one inch from shaft center. Assuming that the engine in question 
was capable of delivering 10 horse-power to its crankshaft, at a speed 
of 2,000 revolutions per minute, and that we wish to find the pull 
available at the driving face of a 6-inch diameter, flat belt pulley, 
attached to the engine crankshaft, we can substitute known values 
and have the following expression: 


10 X 63,024 
2,000 


630,240 , 

- or 315 inch-pounds 

2,000 j 


Dividing this value by the radius of the pulley, or 3 inches, gives 
us a pull equivalent to 105 pounds at the pulley surface. Ii this 
could be transmitted without loss directly to the 18 inches diameter 
driving pulley on the rear wheel, we would have a pull of 105 pounds 
on the surface of that member at 9 inches radius from traction wheel 




104 


Motorcycles , Side Cars and Cyclecars 


center. Owing to the difference in size between the pulleys, the driven 
member would turn at but one-third the speed of the driving member 
on the engine shaft, or 666.66 revolutions per minute. Even though 
the wheel turns slower, the torque, one inch from the traction wheel 
center, would be equivalent to 10 horse-power, as while it would be 
945 inch-pounds, the speed of the rear wheel is but one-third that of 
the engine shaft, and therefore the torque should be three times as 
much. If the amount of power remains constant, the torque or pull 
increases as the speed is reduced, and diminishes as the speed of rota¬ 
tion is augmented. Torque or pull is always greatest near shaft 
center, as for example, at one-half inch radius it is twice as great as 
at one-inch radius, all other conditions remaining equal. It is usually 
based on one inch radius to facilitate calculation. An engine capable 
of exerting a torque or pull of 315 inch-pounds would only exert 
26.20 pounds pull at 12 inches radius under the same speed and power 
conditions. The torque of large engines is measured in foot-pounds 
in order to simplify figuring, while that of smaller capacity power 
plants is more often expressed in inch-pounds. 

When actual horse-power tests are made, there is a point in every 
horse-power diagram where the torque and horse-power curve lines 
intersect, and an engine is not exerting its greatest torque a't its 
highest rotative speed. It will be noted that the horse-power curve 
in the diagrams at Fig. 47 attains its maximum value at a certain 
point, and from there it drops as the speed increases. This falling 
off in power is on account of the higher mechanical losses in the power 
plant at high speeds due to the increased friction of the parts and also 
thermal losses because of difficulties in scavenging or clearing out the 
cylinder properly and taking in a full charge of fresh gas. As one 
would expect, the torque is greatest at low speeds, and gradually be¬ 
comes less as the speeds of rotation increase. The relation of torque 
and horse-power lines to each other when plotted on charts is clearly 
shown in the diagrams at Fig. 47. In the upper one, the test of a single 
cylinder engine rated at 5 horse-power is shown, while in the lower 
one the results obtained by testing a 9 horse-power nominal rating 
twin-cylinder engine are plotted. 

Such diagrams are not difficult to read, and they are especially 
valuable in presenting a large volume of information in a small space. 


Motorcycle Power Plant Group 105 






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o 500 1000 1300 2000 2500 3000 

/fe*oiur*ort} Minure. 


Fig. 47.—Curves Showing Horse Power of Gasoline Motors at Various 

Speeds of Crankshaft Rotation. 


To read these diagrams, it is merely necessary to trace a vertical line 
denoting the speed in revolutions per minute desired to the point 
where it intersects the horse-power curve, and then following out the 

















































































































106 


Motorcycles , Side Cars and Cyclecars 


horizontal line to the right of the chart, where the horse-power de¬ 
livered at that speed will be clearly indicated. The same procedure 
is followed in reading the torque, only that the horizontal line is 
followed to the left of the diagram where the torque in pounds at one 
foot radius is outlined. For example, considering the upper chart, it 
will be apparent that if we follow the vertical line indicating 1,300 
revolutions per minute upward, we will find that it intersects both the 
torque and horse-power curves. Following an imaginary horizontal 
line from this point on the diagram to the right, we find that the 
engine in question is developing approximately 4.50 horse-power 
while the torque is about 18 pounds. It will be observed that the 
power plant rated at 5 horse-power will develop 6.33 horse-power at 
2,400 revolutions per minute. 

Another diagram that gives some interesting data pertaining to the 
relation of motorcycle speed in miles per hour and the engine power 
developed is presented at Fig. 48. It will be observed that the maxi¬ 
mum engine power represented by the highest point in the curve is 
obtained at a vehicle speed of approximately 47.5 miles per hour, and 
that from this point to 65 miles per hour the power curve drops ap¬ 
preciably. At 47.5 miles, the engine is delivering 13.9 horse-power, 
whereas at a rear wheel speed corresponding to 65 miles per hour the 
engine is developing but 9.3 horse-power. The horse-power obtained 
by this test is different than that secured by trial of the engine alone, 
and the object was not to ascertain the brake horse-power of the 
engine but the actual power available at the rear wheel for traction, 
which, on account of mechanical losses in the power transmission 
system, would be fully 20 per cent less than the amount of power 
that would be shown by the engine on a brake or dynamometer test 
where the power of the engine crankshaft would be measured instead 
of that proportion of it delivered at the rear wheel. 

A simple rule for finding the torque at one-inch radius from center, 
exerted by a shaft rotated with a given amount of power that can be 
easily memorized, if one assumes a speed of rotation of 1,000 revolu¬ 
tions per minute, is: Multiply the horse-power by 63, which will give 
the pull in inch-pounds, and then divide this product by the distance 
in inches from shaft center to the point of power application, and the 
result is the torque or pull available at that point directly in pounds. 


Motorcycle Power Plant Group 


107 


Reason for Cooling Engine. —It is apparent that power is pro¬ 
duced in an internal-combustion engine by a series of explosions in 
the cylinder. As the temperature of the explosion is over 2,000 deg. 
Fahr. in some cases, the rapid combustion and continued series of 
explosions would soon heat up the metal parts of the combustion 
chamber to such a point that they would show color unless cooling 
means were provided. Under these conditions, it would be impossible 
to lubricate the cylinder, because even the best quality of lubricating 
oil would be burnt. The piston would expand sufficiently to seize in 



Fig. 48.—Chart Showing Horse Power at Rear Wheel of Motorcycle 

at Various Speeds. 

the cylinder and the valves would warp so that they could no longer 
hold compression. Premature ignition of the charge would probably 
take place long before the engine was put out of commission by the 
distortion of the parts. 

The fact that the ratio of engine efficiency is dependent upon the 
amount of useful work delivered by the heat generated from the ex- 





























































































































































































































































108 


Motorcycles , Side Cars and Cyclecars 



Mv)\\\er 


Wet 
VaWe 


Covc\pves^\on Re\ie^ Cot.k 

CAtawbfcV Caps 

Cooling Flanges 

Exhaust 
Pipe 


Fig. 49.—Typical Single Cylinder Motorcycle Power Plant, Showing 
Arrangement of Cooling Flanges to Increase Radiating Surface 
of the Cylinder, 







TOO 


Motorcycle Power Plant Group 

plosion makes it important that the cylinders be cooled to a point 
where the cylinder will not be robbed of too much heat. The losses 
through the water jacket of the average water-cooled automobile 
power plant are over 50 per cent of the total fuel efficiency. While 
it is very important that the engine should not get too hot, it is equally 
desirable that it is not cooled too much. The object of cylinder cool¬ 
ing is, therefore, to keep the heat of the cylinder metal below the 
danger point but at the same time keep the engine hot enough to 
obtain maximum power from the gas burnt. 

Air or Water Cooling.— -The method of abstracting the heat 
from the cylinder generally employed in the small motors used in 
motorcycle propulsion is by means of direct air cooling, though on 
the larger motors, sometimes used in cycle car and light automobile 
service, the heat is absorbed by water circulated around the cylinders 
through a suitable jacket which keeps it confined against the heated 
portions. In an air-cooled engine, the application of the air to the 
cylinders is direct, and there is no intermediate transfer of heat from 
the cylinder wall to the radiating surfaces by means of water. Any 
water-cooling system must, of necessity, be indirect, as after the water 
is heated it must pass through a radiator where it is subjected to the 
cooling influence of air currents to reduce its temperature, and make 
it available for further use. In a motor which employs a water-cooling 
system, there is a certain loss of heat to the water jacket which is 
called “Jacket Lo^ss,” and the amount of heat wasted in this manner 
depends upon the difference in temperature between the heat of the 
explosion and the heat of the cylinder wall. As water loses its cooling- 
efficiency when it boils, the temperature of the water jackets, and 
consequently the wall of the water-cooled cylinder, must be main¬ 
tained at a point below 212 deg. Fahr. which is the boiling point of 
water. The temperature of the cylinder wall of an air-cooled motor 
may be readily and safely maintained at a temperature nearly 150 
degrees higher. This would indicate that, with a reduced heat loss, 
an air-cooled motor would be more efficient than a water-cooled 
form. Then, of course, the features of simplicity that are so necessary 
in motorcycle design cannot be readity obtained if the water-cooling 
system is employed because in its simplest form it requires a radiator 
to cool the water, and suitable piping to conduct the water from the 


110 


Motorcycles, Side Cars and Cyclecars 


engine cylinder water jacket to the point where the heat is radiated 
into the air. As an air-cooled engine can be made considerably lighter 
than a water-cooled form, and as the direct system of cooling has 
demonstrated that it is thoroughly practical for the small engines 
used in motorcycle work, it does not seem necessary to provide motor¬ 
cycle motors with water jackets. All of the American motorcycles 
use the air-cooling method, though several foreign machines have 
water-cooling systems. 

Efficiency of Air=Cooled Motors. —The air-cooled motor is more 
efficient than the water-cooled forms, because in any internal com¬ 
bustion engine it is the heat energy of the fuel that is converted into 
useful work. This transformation is brought about by the rapid 
combustion or burning of the fuel which is often called “an explosion.” 
The rapidly burning gases develop high pressures which produce 
power, as we have seen, by acting on the piston and the reciprocating 
parts. The temperature and pressure of the explosion both fall very 
rapidly, on account of the rapid escape or transfer of heat through 
the walls of the cylinder and the piston head. A certain amount of 
heat loss is a necessary evil that cannot be avoided in any internal 
combustion engine, and as previously stated, efficient lubrication 
cannot be obtained if the cylinders get much hotter than 400 deg. 
Fahr. A cylinder may be allowed to heat up to 350 deg. Fahr. and 
still be on the safe side as far as effective lubrication is concerned. 
In comparing the efficiency of air and water cooled motors, a good 
method of doing this is to base the values on the amount of mileage 
possible on a given fuel consumption. An air-cooled engine will use 
a maximum of 0'.80 of a pound of gasoline for each brake horse-power 
hour at half load, and 0.60 of a pound of gasoline for each brake 
horse-power hour developed at full load. The average water-jacketed 
automobile engine will use from 1 to 1.50 pounds of fuel at half load, 
and from 0.90 to 1.20 pounds per brake horse-power hour at full load. 
From the foregoing, it will be apparent that the air-cooling system 
is more efficient and economical than the water-cooling methods, and 
in view of its simplicity it is not difficult to understand why it is almost 
universally used in motorcycle power plants of American design. 

Air=Cooling Methods. —Air cooling may be obtained by two 
methods: either simple radiation, or combined radiation and con- 


Ill 


Motorcycle Power Plant Group 

vection. The former system is used only on motors of a stationary 
type that are not provided with a cooling fan. The most widely used 
system is a combination of radiation and convection. Radiation 
simply means that the heated air rises from the hot cylinder because 
it is lighter than the cooler air which takes its place. Convection 
means cooling by air in motion, and, obviously, wherever convection 
is used there must, of necessity, be included the radiation principle. 
The method generally used cn motorcycles where the power plant is 
exposed to the air, and where the cylinder is swept by air drafts or 
currents created by the rapid travel of the machine, is to augment 
the normal available radiating surface of the plain cylinder by pro¬ 
viding cooling flanges as indicated at Figs. 49 and 50. 

These flanges not only surround the entire cylinder exterior but also 
cover the valve chamber and the cylinder head. By the use of these 
members, the area of radiating surface is largely increased, and while 
air has considerably less capacity for absorbing heat than water, the 
surface from which the heat is radiated may be increased to such a 
point by judiciously placed flanges so the heat will be dissipated fast 
enough to keep the cylinder from overheating. The cooling flanges 
may be of the same diameter the entire length of the cylinder, as 
shown at Fig. 49, or they may become less in diameter as the cylinder 
temperature decreases, as shown at Fig. 50. They are widest at the 
combustion chamber, and taper down in diameter to but little more 
than that of the cylinder at the bottom of that member. On some 
types of flange-cooled engines, the designers drill holes through the 
flanges as indicated at Fig. 51, and while these materially reduce the 
effective radiating surface it is claimed that there is more opportunity 
for the cooling-air current to pass around and between the flanges, 
and thus superior cooling is obtained. The air-cooling flanges on 
most motorcycle power plants are placed horizontally, or at right 
angles to the cylinder center line, though in some forms, where the 
c^vlinder is inclined, the flanges are disposed at an angle to the cylinder 
wall so that they will be approximately horizontal when the power 
plant is in position. On some forms of double cylinder opposed 
engines, the flanges run the length of the cylinder, in order to promote 
free circulation of air. Where air-cooled motors are protected by a 
hood or bonnet, as in cyclecars and light automobiles, it is customary 


Motorcycles , Side Cars and Cycle-cars 


112 



/ 


lA&^neto 




si\/a\ve 

E-inHausi Va\veChpeY&l\\v$ Rod 


Fig, 50,—The Precision Overhead Valve Air-Cooled Motor Having 
Cooling Flanges of Graduated Diameters. 












Motorcycle Power Plant Group ] ] 3 


Fig. 51.—Showing Method of Per¬ 
forating Flanges to Facilitate 
Air-Cooling. 


to provide a cooling fan driven 
from the engine crankshaft to 
keep a constant draft of air in 
motion around the engine cylin¬ 
ders. In some automobile power 
plants the cylinders have been 
encased in sheet metal jackets, 
and air currents from a blower 
are made to circulate through 
these jackets and around the 
cylinders, but this is not neces¬ 
sary on motorcycles. Copper¬ 
plating the cylinders increases 
the rate of heat transfer to the 
air. Radiation may also be 
augmented by painting the cyl¬ 
inders with a dull black stove 
polish. 

VVater=Cooling Methods. —When a liquid is employed for cooling 
it is circulated through jackets which surround the cylinder castings, 
and when the excess heat is absorbed, the hot liquid is led to a cooler 
where the heat is abstracted from it by means of air currents. The 
cooled liquid is then taken from the cooler and again circulated around 
the cylinders of the motor. The view of a typical one-cylinder motor 
at Fig. 53 shows the arrangement provided for water cooling by radi¬ 
ators attached to the engine cylinder. 

Two methods of keeping the cooling liquid in motion are used. The 
simplest system is to utilize a natural principle that a hot liquid being- 
lighter than a cold one will tend to rise to the top of the cylinder when 
it becomes heated, while cool water takes its place at the bottom of 
the water jacket. The more complicated system is to use a positive 
circulating pump of some form which is driven by the engine to keep 
the liquid in circulation. 

Some eminent motorcycle designers contend that the rapid circula¬ 
tion of liquid obtained by means of a pump may cool the cylinders 
too much and the temperature of the engine may be reduced to a 
point where its efficiency will be somewhat lower than if the engine 



























114 


Motorcycles , Side Cars and Cyclecars 


were allowed to run hotter. For this reason, some foreign engineers 
use the natural method of water circulation. The cooling liquid is 
applied to the cylinder jackets below the boiling point and the water 
issues from the top of the jacket after it has absorbed enough heat to 
raise it just about to the boiling point. The simplicity of the thermo¬ 
syphon system of cooling makes it specially adapted to motorcycles 
and other light vehicles. With this system of cooling, it is necessary 
to use more liquid than with pump-circulated systems, and the water 
jackets of the cylinders, as well as the water spaces in the radiator 
and the water inlet and discharge manifolds, should have greater 

capacity and be free from sharp 
corners that might impede the 
flow of liquid. 

A system of cooling in which 
a pump is depended on to pro¬ 
mote circulation of water is 
sometimes employed in cyclecar 
practice. The radiator is gener¬ 
ally carried at the front end of 
the frame, and serves as a com¬ 
bined Avater tank and cooler in 
most cases. It is usually composed 
of upper and lower water tanks, 
joined together by a series of 
pipes, which may be round and provided with a number of corrugated 
flanges to radiate the heat, or which may be flat in order to have the 
water pass through in thin sheets and cool more easily. The cold 
water which settles at the bottom of the cooler is drawn from the lower 
part of the radiator by a gear-driven pump and is forced through a 
manifold to the water jackets surrounding the exhaust valve chamber 
of the cylinder. As the water becomes heated, it passes out of the 
top of the water jacket into the upper portion of the radiator, but as 
a general rule the rate of circulation is dependent upon the power and 
speed of the pump rather than the degree of temperature of the water. 
On account of the more rapid flow of' liquid, the radiator and piping 
may be of less capacity than when the simple thermo-syphon is 
employed. 



Fig. 52.—View of Green-Precision 
Motor With Radiators At¬ 
tached to the Sides of the 
Water Jacket. 












Motorcycle Power Plant Group 


115 



Fig. 53 .—Complete Water-Cooled Power Plant With Radiators 

Integral. 


OuUebb To 

Tj»k 

xhavst Pipe 


R&dhalcors 


V/atev 3at^eled 
Cylinder 




Mu^f\ev 







110 Motorcycles , Side Cars and ( 1 y cl rears 

Some typical water-cooled motors that have been designed for 
motorcycle use abroad are shown at Figs. 52 to 54 inclusive. The 
engine shown at Fig. 52 in place on the motorcycle frame is the same 
as that depicted at Fig. 53, and it will be observed that the radiators 
which serve to cool the water are attached directly to the sides of the 
water jacket. There is ample opportunity for the air currents to pass 
through the radiators, and it is possible to carry a reserve supply of 
water in a tank attached to the top frame bar which may be used as 
an auxiliary source of supply by connecting it to the water outlets at 
the top of the radiator that are clearly depicted at Fig. 53. On very 
small engines, it will be unnecessary to provide any water container, 
a‘s the radiators themselves may hold enough water to secure adequate 
cooling. 

Both of the engines depicted at Fig. 54 are of the two-cycle form 
and are shown in the position they occupy in the motorcycle frame to 
which they are fitted. That at A is the Rex motor, and it will be ob¬ 
served that the radiator is placed at the front end of the machine just 
back of the steering head and follows the diagonal tube extending 
from the steering head to the motor crank-case. The bottom of the 
radiator is connected directly to the bottom of the water jacket, and 
the heated water from the top of the cylinder passes through suitable 
pipes to the top of the radiator. The cooling system depicted at B 
is that of the Scott motorcycle, and the disposition of the radiator 
and arrangement of water piping is practically the same as in the 
example previously considered. 

The engine depicted at Fig. 53 is a four-cycle form while those out¬ 
lined at Fig. 54 are two-cycle engines which are said to be more 
difficult to cool successfully by air than the conventional form of 
four-stroke engine in which one entire stroke of the piston is devoted 
to clearing out the burnt gases from the cylinder Avhile another full 
stroke is utilized in drawing in a cool charge of fresh gas. The Shickel 
engine, an American two-cycle form shown at Fig. 58, is cooled suc¬ 
cessfully by air, and in view of the fact that air cooling has been 
applied successfully to motor truck engines having 4.50-inch bore 
and operating on the two-cycle principle, it is apparent that it should 
be more successful and practical on the smaller two-stroke engines 
employed as motorcycle power plants. 


Motorcycle Power Plant Group 


117 



and Water Connections. 








































118 


Motorcycles , Side Cars and Cyclecars 


Features of One=Cylinder Motors. —The single-cylinder engine 
offers a main advantage of extreme simplicity. This is of considerable 
importance in the lighter motorcycles that are to be operated by in¬ 
experienced riders. Among some of the disadvantages that may be 
cited against the single-cylinder power plant are greater weight in 
proportion to power developed, lack of even power application because 
only one stroke out of four made by the piston is effective. A one- 
cylinder engine lacks the even turning moment and steady running 
qualities that a multiple-cylinder power plant possesses. If run faster 



Fig. 55.—Typical Complete Power Plant Unit Adapted for Attachment 

in Standard Diamond Frame Bicycle. 


or slower than the critical speed for which it was designed, there will 
be considerable vibration. Despite these faults, the single-cylinder 
engine is very practical in applications to light and medium-weight 
machines, and ample power may be obtained to cope with any con¬ 
dition ordinarily met with in road service. Typical one-cylinder 
engines are illustrated at Figs. 55 to 57, inclusive. 








































Motorcycle Power Plant Group 


119 


Fig. 56.—Power Plant of Single Cylinder Indian Motorcycle. 

If of the two-cycle type, one will obtain the same even torque and 
steady application of power with one cylinder as provided by a two- 
cylinder opposed four-cycle engine, and steadier running than pro¬ 
vided by most V-twins, though one must sacrifice some of the flexi- 



Oil Pu 


Iftlet Valve G 


age 

inlet PI 


Spark Plug 


Carburetor 


aoneto 

VW JO 

Drive 
Gce&rs 












120 


Motorcycles , iSiefe Cars and Cyclecars 


bility and quick get-away of the four-cycle power plant to obtain the 
advantages of the simpler two-stroke motor. The Schickel two-cycle 
motor construction is shown at Fig. 58. 

Advantages of Multiple=Cylinder Motors. —Power is obtained 
in the multiple-cylinder motor by using a number of cylinders instead 
of one large member. The cylinders are arranged in such a way that 
any multiple-cylinder motor may be considered as a number of single- 



Fig. 57 .—Typical Single Cylinder Power Plant of English Design. 


cylinder engines joined together so that one cylinder starts to deliver 
power to the crankshaft where the other leaves off. By using a 
number of smaller cylinders, instead of a large one, all of the revolving 
parts may be made lighter, and the reciprocating members are easier 
to balance because the weight of the parts in one cylinder often 
































































































































Re\te( VaWe 


Motorcycle Power Plant Group 


121 



















































































































122 


Motorcycles , Side Cars and Cyclecars 


counter-balances the reciprocating mass in the other that works in 
connection with it. 

Multiple-cylinder engines may be run faster than single-cylinder 
ones of the same power, are not so heavy in proportion to the power 
developed and produce a more even turning effect at the crankshaft. 
No matter how well designed the single-cylinder power plant is, the 
power impulses will come in jerks, and a very heavy fly-wheel member 
or pair of fly-wheel members is needed to equalize the intermittent 
power strokes. In a multiple-cylinder engine, where the explosions 
follow each other in rapid succession, the power application is ob¬ 
viously much more even. A single-cylinder engine will give but one 
useful power stroke when of the four-cycle type, to every two revolu¬ 
tions of the crankshaft. A two-cylinder motor will give one explosion 
every revolution, though these are not always evenly spaced, the 
regularity and evenness of firing being largely dependent upon the 
arrangement of the cylinders. 

Types of Two=Cylinder Motors. —Most two-cylinder motorcycles 
employ engines of the V-type, i. e., with the two cylinders placed at 
an angle, and converging to a point at which they contact with the 
crank-case of the motor. In England, there are a number of machines 
which employ horizontal cylinders, and one or two makes have been 
evolved in which the two-cylinder engine has vertical or upright 
cylinders. We have seen that in a single-cylinder engine consid¬ 
erable dependence is placed upon a fly-wheel which stores up energy 
and which tends to even up or equalize the intermittent power ap¬ 
plication derived from but one explosion every two revolutions. We 
have also learned that multiple-cylinder engines produce more uni¬ 
form torque because explosions follow each other more rapidly. Where 
two-cylinder motors are employed, the arrangement of the cylinders 
and the crank throws with relation to each other has material in¬ 
fluence upon the evenness of operation. 

For example, in an engine where one of the cylinders fires during 
one-half of a revolution and the second cylinder produces a power 
impulse directly after it or while the first cylinder is on its exhaust 
stroke, it is evident that the engine crankshaft will have to describe 
almost a continuous revolution before it can receive another power 
impulse. While the crankshaft receives what would be equivalent to 



Motorcycle Power Plant Group 


123 


a power impulse each revolution, in reality it receives two power im¬ 
pulses in one revolution and none during the second. When the 
cranks are arranged as shown at A, Fig. 60, and the cylinders are 
vertical, the explosions will follow each other without any appreciable 
interval, and the only advantage obtained is that the cranks, con¬ 
necting rods and pistons balance much better than in some other 
forms. While the vibration due to poor mechanical balance is elimi¬ 
nated to some extent with this construction, a certain unevenness of 
running obtains on account of the way the explosion occurs. 

When the cranks are set on the same plane as shown at B, and both 
of the pistons move up and down together, it is possible to obtain a 



Fig. 59.—Diagram Showing the Advantages of Multiple Cylinder 
Engines in Obtaining Uniform Power Delivery. 


good firing order, i. e., an explosion would occur the first part of the 
first revolution in one cylinder and the first part of the second revolu¬ 
tion in the other cylinder. The explosions are separated by equal 
intervals of time, and the power application is much more uniform 
than obtained from the type shown at A. The disadvantage of this 
method of construction is that the mechanical balance is far from 
ideal, and counter-weights must be provided to reduce the vibration 
incidental to both pistons moving up and down together. 

With the double opposed motor which is shown at C, the crank-pins 
are arranged at 180 degrees, and the explosions occur at regular in¬ 
tervals and with the same firing order as prevails in the construction 
shown at B. This form of motor also has a good mechanical balance. 
With the V-type of motor it is apparent that the smaller the angle 
between the cylinders the more evenly spaced the firing sequence 
becomes, though the mechanical balance is more difficult to obtain 
when the degree of angularity is small. In a motor with the cylinders 













124 Motorcycles, Side Cars and Cyclecars 


/60< 


360 ■ 


A : 


/"Cflrrdtr U J l U 

, fi'rrx . //rrs. 



Cyhndtr 

I - * 


^Cf/,nJtr 

- » - 1 - 



•Cyfinder Tires 


nj! Cylinder Tras 

—4.« 




"Oii^atrr.r 

■4 r~*c r M 

■ksf'ru 

r 

1 - 

FH . 


"CfhnOtr f/>tt I'^CfinOtrnfrj 

rr 4^-t -| 


Fig. 60.—Diagrams Illustrating Various Arrangements of Crankshafts 
on Two Cylinder Motorcycle Power Plants. 
































































































































Motorcycle Power Plant Group 


125 


at an angle of 90 degrees to each other and with the two connecting 
rods working on the same crank-pin, the mechanical balance is good 
but the impulses occur very close together. The better mechanical 
balance is obtained because the pistons partially balance each other, 
and a slightly better firing order prevails than in the arrangement 
shown at A, as there is an interval corresponding to about one-quarter 
of a revolution between the explosions. When the cylinders are set 
at an angle of 50 degrees, as indicated at E, the impulses are almost 
equally divided between the blank spaces as indicated in the diagram. 
It is possible to have the cylinders set so the explosions are spaced 
even more regularly, as with the cylinders at 41 degrees, which is said 
to be the prevailing angle in this country. 

The same difficulties are met with in securing good mechanical 
balance as in the form shown at B, as it is imperative that counter¬ 
weights be fitted to balance the reciprocating mass to some extent and 
reduce vibration. The great advantage of the V-twin motor is that 
it is a form that may be easily installed in the motorcycle frame, and 
while the balance is far from perfect it is sufficiently good if the 
counter-weights are intelligently applied, so a very practical power 
plant is secured. The original twi n-cylinder motorcycle power plant, 
and one of the first multiple-cylin cler gasoline engines, is depicted at 
Fig. 61, C, and is an adaptation of the single-cylinder form evolved 
by Daimler, and clearly outlined at A and B. The cylinders in this 
Daimler motor were placed at an angle of approximately 15 degrees, 
which is considerably less than present practice. 

The engine shown at Fig. 62 is utilized on the Triumph, an English 
design, and the crank pins are disposed at an angle of 180 degrees. 
The motor is set in the frame with its crankshaft at right angles to 
the top frame tube, and not parallel with it as might be expected. 
The crankshaft carries an outside fly-wheel at one end and a sprocket 
for chain drive at the other. The inlet valves are at the front of the 
cylinders and the exhaust valves are at the rear. Both are operated 
by a camshaft which is driven by a spiral gear from the crankshaft. 
A typical twin-cylinder V-engine of American design, that may be 
considered a good example of established practice and which has 
received wide application, is shown at Fig. 63. 

One of the most efficient of the British light-weight motorcycles Is 




120 


Motorcycles , Side Cars and Cycle cars 



Internal Combustion Power Plants. 































































































Motorcycle Power Plant Grou/p 127 

provided with the two-cylinder power plant shown at Fig. 64 in which 
the cylinders are placed horizontally and opposed to each other. The 
crankshaft, which is depicted in the sectional view of the crank-case 
at the left of the illustration, has two crank-pins placed at an angle 
of 180 degrees, and is mounted on ball bearings to insure free running. 
A distinctive feature of the design is the method of mounting the 
valves in valve chambers that are inclined so the valves may be 
actuated from the lower portion of the cam gear case. The method 
of ribbing the cylinders to secure more effective cooling permits the 
air draft induced by cycle motion to reach practically all parts of 

the cylinders, which would not be 
possible if the flanges were applied 
in the conventional manner that 
proves so effective on vertical 
cylinders. This is a very compact- 
engine that is capable of deliver¬ 
ing a uniform torque, and that 
operates with very little vibra¬ 
tion, as the even spacing of the 
explosions and large external fly¬ 
wheel make for very easy run¬ 
ning. The method of magneto 
and valve-operating cam drive 
may be readily ascertained as 
well as other ingenious details 
of design by studying the repro¬ 
duction of the maker’s engineering drawing that so clearly outlines 
all details of construction. 

One of the most distinctive of the unconventional power plants 
used for motorcycle propulsion is the Scott two-cycle, depicted at • 
Fig. 65. This shows an early model in which a combined air and 
water cooling system was employed, the liquid being depended on 
to keep the water-jacketed head cool while the cylinders were pro¬ 
vided with cooling flanges of generous proportions. The cylinders 
are mounted side by side, one each side of the engine center line, 
which coincides with the center line of the machine. Attention is 
directed to the small size of the crank-cases, which is necessary to 



Fig. 62.—The Triumph Two Cyl¬ 
inder Motorcycle Power Plant, 
an Unconventional English 
Design. 















128 


Motorcycles, Side Cars and Cyelecars 



Fig. 63.—Complete Power Plant Assembly Employed on Two 

Cylinder Indian Motorcycle. 

insure adequate preliminary compression of the charge before it is 
transferred from the engine base to the cylinders. The fly-wheel is 
mounted between the two cylinders, and carries the driving sprockets 
on its hub which also forms a connecting coupling between the two 
















Motorcycle Power Plant Group 


120 



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• H 




































































































































































































ISO Motorcycles , Side Cars and Cyclecars 

cranks, the assembly forming a built-up crankshaft with the crank- 
pins at the extreme ends. The arrangement of the ports for the 
passage of the gases in and out of the cylinder and the method of con¬ 
trolling them by the piston movement is clearly shown in the side 
sectional view through one of the cylinders. With the piston in the 
position shown, the exhaust ports are fully open for discharging the 
burnt gases and the inlet ports at the opposite side are also uncovered 
to permit the gas compressed in the engine base to by-pass into the 
cylinder through the transfer passage. The piston is provided with 
a deflector to direct the entering fresh gas to the top of the cylinder, 
and prevent it passing out of the open exhaust ports opposite the 
point where it first enters the cylinder. When the piston reaches the 
top of its stroke, another row of ports is opened by the bottom of the 
piston and the crank-case is charged with gas. When one piston is 
up, the other member is down and the pistons balance each other. 
An explosion is obtained in each cylinder every revolution, which in¬ 
dicates that this engine should provide the same even torque as ob¬ 
tained from a four-cylinder engine of the four-stroke pattern, inasmuch 
as the crankshaft receives two impulses each revolution. 

Four=Cylinder Forms. —The real value of a multiple-cylinder 
motor is more apparent when four or six cylinders are used, because 
in the former one obtains a power impulse every half revolution of the 
fly-wheel, while in the latter three power strokes are delivered every 
revolution. The diagram presented at Fig. 59 compares in a graphic 
manner the useful power impulse of engines having one, two and four 
cylinders respectively. The shaded parts represent periods where 
power application obtains, while the unshaded portions represent no 
power. In the one-cylinder engine, it will be evident that less than 
one-quarter of the cycle represents useful energy. In the two-cylinder 
engine the explosions may be evenly spaced, but are separated by 
appreciable spaces where no power is developed. 

Even in the four-cylinder engine there are periods (corresponding 
to the early opening of the exhaust valves on the power stroke) where 
no useful energy is directed against the crankshaft. The torque or 
power application is uniform enough for all practical purposes, except 
where the utmost refinement is desired, as in high-grade motor car 
power plants. In the six-cylinder engine there are no periods in the 


Motorcycle Power Plant Group 


131 



✓ 


Fig. 65.—Sectional View Showing Arrangement of Parts in Scott Two-cycle Power Plant. 



















































































132 


Motorcycles , Side Cars and Cyclecars 


cycle of operation where the crankshaft is not positively driven. In 
fact, the explosions overlap each other, and a very smooth-acting 
power plant is obtained. For motorcycle service, however, a four- 
cylinder motor will prove to be very satisfactory, and will operate 
with minimum vibration, and, in view of the very satisfactory opera¬ 
tion of the ordinary V-twin power plant, it is open to question if the 
four-cylinder motor offers marked enough advantages to compensate 



Fig. 66.—Manifold Side of the Henderson Four Cylinder Motorcycle 

Power Plant. 


for its added complication. Of course, there are riders who want the 
best there is, regardless of cost, and where maximum silence, freedom 
from vibration and even power application are desired, it is evident 
that the four-cylinder power plant best fulfills the requirements. 

The four-cylinder motor utilized in the Henderson motorcycle, an 
American design previously illustrated, is shown installed in the frame 
at Fig. 66 when viewed from the valve side, and in section to show 
practically all the details of construction at Fig. 67. In general 

















Motorcycle Power Plant Group 



133 


Fig. 67.—Sectional Views Defining Internal Construction of Henderson Four Cylinder Motorcycle Power 

Plant. 

































































































































































































































































































134 


Motorcycles , Side Cars and Cyclecars 


arrangement of parts, this power plant follows the lines established 
in automobile practice. A sectional view of the F. N. four-cylinder 
engine, which shows the practical application of a five-bearing crank¬ 
shaft and the arrangement of the crank-pins, so two pistons are going 
down while the other two are on their up stroke, is presented at Fig. 
68. It will be noticed that the Henderson crankshaft, while it has 
four crank throws, is a three-bearing form, having one main journal 
at the center and one at each end, whereas the F. N. design has a 


Inlet VaW 

Dovne 

Cool m 
Plawdes 




Mam Rearing Cyavi\\sV>a\t 'tbase 


Plug 

Cylinder 
Piston 
•’Wmtpm 

„Connect\no 

Rod * 



FWw\\«e\ 


Fig. 68.—Sectional View of the F. N. Four Cylinder Motor. 


bearing between all crank throws as well as at the ends of the crank¬ 
shaft. 

Power Plant Support and Location— We have seen that in the 
early days the designers considered the gasoline motor an attachment 
to the bicycle, and that it was disposed of in numerous ways, few of 
which were really satisfactory and effective. The average rider who 
is familiar with present practice may not consider that power plant 
location or support is much of a problem, and in view of the remark- 




















































































Motorcycle Power Plant Group 135 

able unanimity of opinion regarding power plant placing in modern 
machines, this view is, to a certain extent, justified, though those who 
have been identified with motorcycle construction long enough know 
that considerable experimentation was necessary before the designers 
of power-propelled cycles were able to place the power plant to the 
best advantage. As soon as designers realized that the power plant 
was an important component part of the vehicle and that it should 



Fig. 69.—The Peugeot (French) Motorcycle Power Plant Installed in 

Frame. 

be incorporated in the design, the diamond frame was abandoned, and 
special frame constructions evolved, in which provision was made 
for the secure anchorage of the engine base. 

The non-technical reader has no comprehension of the amount of 
stress present at the points of motor support and why these must be 
amply strong, but some idea may be gained if one considers that all 
the time the motor is driving the rear wheel there is a reaction 
or pull on the engine fastenings that tends to loosen it from its sup- 








136 Motorcycles , Side Cars and Cyclecars 

ports. This force is equal to that exerted by the motor to drive the 
motorcycle. In addition to the torque reaction, as this force is called, 
there is an added twisting stress due to the common system of taking 
the power from one side of the motor only, which tends to turn the 
motor on a vertical axis, whereas the torque reaction tends to rotate 
the power plant on a horizontal axis at the center line of the crank¬ 
shaft. Besides securing ample strength in the design of motor sup¬ 
ports, it is also important to mount the power plant in a way that 


Fig. 70.—Valve Side of the Excelsior Twin Cylinder Power Plant. 

will permit of its ready removal from the frame for repairs. It is also 
desirable to have the motor fastened securely enough so the frame 
structure will resist its tendency to vibrate at all speeds except at the 
critical speed for which the balance weights were calculated, there¬ 
fore some makers anchor the cylinders to the frame tubes as well as 
the engine base. 

The loop frame design is widely employed because the motor may 
be removed from the frame without disturbing the integrity of the 











Motorcycle Power Plant Grou/p 


137 


frame structure. Designers who favor this method of motor support 
also contend that the engine base is better protected when mounted 
above a substantial frame tube than when suspended so it forms part 
of the frame. The installation of the Peugeot engine in a loop frame 
of substantial design is shown at Fig. 69, and in this construction it 
is not believed necessary to anchor the cylinders to the frame in any 
way. When the cylinders are not secured to the frame and a loop 



Fig. 71.—Valve Side of the Yale Twin Cylinder Power Plant. Note 
’ Design of Cooling Flanges, Which Permit an Unobstructed Flow 
of Air Over the Cylinders. 









138 


Motorcycles , Side Cars and Cyclecars 


frame is employed, it is possible to remove a cylinder from the crank¬ 
case, in many cases, without removing that member from the frame. 
The crank-case may be made lighter when it is not an integral part 
of the frame, and should the frame weave there is no strain imposed 
on the cylinder as that member is free to move slightly even though 
the crank-case is securely held. 

In the Excelsior machine, the power plant forms a part of the frame, 
and is depended upon to give the frame strength, as that member 
would not be very strong with the engine base removed. Of course, 
the makers contend that there is no need for strength when the motor 
is not in place because at such times the motorcycle is out of com¬ 
mission, but there is always the liability of springing the lower por¬ 
tions of the tubes when they are not supported if the frame is care¬ 
lessly handled when the motor is not in place. A loop frame is much 
stronger than the forms shown at Figs. 70 and 71, when the motor is 
removed, and there is no possibility of distorting the frame. The 
Excelsior motor is supported at five points, and, when in place, the 
structure is very strong. As the lower portion of the crank-case is 
exposed, it is made heavier and stronger than in the forms where it 
is protected by the frame tube loop, and this added strength has a 
favorable bearing on general rigidity of the assembly. The motor 
is supported at three points on the crank-case, two being at the rear 
and one at the front, and each of the cylinders is attached to the 
frame member below the tank by substantial clips. This method of 
attachment is very valuable in open-frame machines where there is 
some opportunity for frame weaving, especially if the power plant 
retaining bolts loosen even a slight amount. 

While the attachment of the cylinders steadies the motor wonder¬ 
fully, and holds it in place, some who do not favor this construction 
contend that the expansion of the cylinders when heated renders it 
imperative to have the upper end of the cylinders free to move under 
its influence. This objection seems to be more theoretical than real 
because machines with the cylinders anchored have given just as good 
service in practical application as those that were free to expand 
unhindered. 

The Yale power plant, shown at Fig. 71, is anchored to the frame 
in much the same manner as the Excelsior, as the rear end of the 


Motorcycle Power Plant Group 


139 


engine base is attached to substantial plate members firmly secured 
to the crank hanger, while the front portion is provided with a lug 
fitting between the jaws of the fork attached to the lower end of the 
diagonal frame tube. The water-cooled power plant of the Regal- 
Green motorcycle, an English design depicted at Fig. 72, also forms 
part of the frame assembly and is fastened in much the same manner 
as the Excelsior and Yale power plants. The method of installing 



Fig. 72.—Showing the Application of the Precision Water-Cooled 

Motor on Regal-Green Motorcycle. 

a four-cylinder power plant is exemplified at Fig. 66 which shows the 
fastenings that hold the Henderson motor in place. The lower portion 
of the frame is composed of two parallel tubes which converge at the 
front end to the steering head, and as there is sufficient space between 
them for the comparatively narrow crank-case possible with the small 
four-cylinder design, this member may be provided with suitable lugs 
or arms cast integral which rest on the frame tubes and be securely 




140 


Motorcycles , Side Cars and Cyclecars 



InWd VaW Rocker Arm 

lnWtV»\ve lapped ftod 

/ /IrdvJtA’iori Pipe 

SpavU P\og Wauredov /«j 


\n\ed V&tae ^Joto' 




Cs|UnAev Head 


CoeWn^ Places 


KoWev \J!ve&m<g 
Gwikp* 


' ' "% A 


■ 5 v ■ 

Aniel S/aWe 
Ikpressw ’V-^ 
'Wve \bome 
-Valv«. C-age | : > 

Va\ve Spr’md 
Inlet Vidve. 

• m 
\ 

Cylinder . 
^cadt ;.f 


'Exhaust. Valve 

. " / 

PU^neto 


Piston R m^fs 
Pisdon—' 
V/nslpm 


ConnecAincf Rod 


OvAnVCASe 


F\vwV»ee\ 


in 


^ A Magneto Qme 
Idler dears 


Magneto Wive 
Pinion 


Fig. 73.—Part Sectional View Showing Arrangement of Important 
Internal Parts of Two Cylinder Indian Motorcycle Power Plant. 

retained by bolts or studs passing through the tube and crank-case 
extensions. A very secure four-point suspension system is obtained 
in this manner, and owing to the smooth running and lack of vibra¬ 
tion, incidental to the employment of a four-cylinder engine, it is not 










141 


Motorcycle Power Plant Group 

necessary to anchor the cylinders to the frame in any way except by 
the necessary bolts which keep them in place on the engine base. 

Motorcycle Engine Parts and Their Functions— In order that 
the non-technical reader may become thoroughly familiar with the 
principles of operation and appearance of the various parts of motor¬ 
cycle power plants a number of forms will be described and the func¬ 
tions of the various parts made clear. The engine at Fig. 73 is shown 
in part section as the crank-case and the lower part of one of the 
cylinders is cut away, while the other cylinder is sectioned through 
the valve chamber. The engine consists of an engine base, which 
also serves as a crank-case to which the two cylinders and all other 
parts are attached. The members inside the cylinders that recipro¬ 
cate up and down, and which receive the force of the explosion, are 
termed “pistons,” and there is one in each cylinder. The recipro¬ 
cating movement of these pistons is converted into a rotary movement 
of the crank-pin by means of connecting rods which oscillate at their 
upper ends on wrist pins that pass through suitable bosses in the 
piston. The inlet valve, which is the member through which the gas 
is admitted into the cylinder is carried in a valve cage which in turn 
is installed in an air-tight dome which is utilized to press the valve 
cage firmly against the seating in the cylinder head. The inlet valve 
is normally kept seated b}^ a valve spring, and is opened at the proper 
time by the inlet valve depresser, which is worked by the inlet valve 
rocker arm. The rocker arm is operated by a tappet rod which extends 
to the top of the cylinder from the timing gear case. The exhaust 
valve is the member controlling the port through which the burnt 
gases leave the cylinder, and this is raised from its seat at the desired 
period in the cycle of operations by a push rod that bears against the 
lower portion of the valve stem. The exhaust valve is kept seated in 
the same manner as the inlet valve though the spring is stronger. 

The spark plugs which are inserted in the combustion chambers are 
employed to explode the gas with a spark derived from the magneto 
which is driven by a train of gearing from the crankshaft. The 
cylinder heads, as well as the cylinders, are provided with cooling 
flanges and are held in place on the cylinders by bolts extending to 
the crank-case which also serves to hold the cylinders firmly by clamp¬ 
ing them between the heads and engine base. The fly-wheels are 


142 


Motorcycles, Side Cars and Cyclecars 



Fig. 74.—Sectional View Outlining Construction of the Reading-Standard Twin Cylinder Power Plant. 




































































Motorcycle Power Plant (Irony 


14,‘5 


employed to steady the action of the engine, and to store up power 
during the idle strokes in order to keep the engine parts in motion 
at such times as there is no useful pressure exerted against the 
piston tops. The carburetor that supplies the explosive gas to the 
cylinders is securely attached to an induction pipe that joins the inlet 
valve domes of the two cylinders. 


Water Jacket 

Inlet Value 

Inlet Value Seat 
Inlet Value Chamber 

Water Jacke 
Inlet Value Stem 

Wrist Pin 
Piston 

Inlet'Value Lifter Rod 

Connecting Rod 

Crank Case 

Crank Arms 
Inlet Value Cam ^ % 
Connecting Rod Cap ^ 


Spark Plug 

Water Outlet 

Combustion Space 
Water Jacket 


Inlet Camj 
Shaft 

Inlet Cam 
Shaft. Gear - 

Starting 
Crank 



Exhaust Value 
Exhaust Value Stem 

Exhaust Value 
Chamber 
Water Jacket 
Value Stem Guide 
Water Inlet 
Value Spring 

Exhaust 
Value 
Lifter 
Rod 

Crank 
Case 

Lifter 
Guide 


Fly Wheel 

'Crank Shaft Searing 
x Exhaust Value Cam 
Crank Case 

Exhaust Cam Shaft Gear 
'Exhaust Cam Shaft 


Fig. 75._Diagram Showing Principal Parts of Single Cylinder Water- 

Cooled T Head Power Plant. 



































































144 


Motorcycles , Side Cars and Cyclecars 


The twin-cylinder power plant, shown at Fig. 74, is practically the 
same in operation as that previously described though the cylinder 
design and location of valves is very much different. In the side 
view, the valve-operating mechanism and the magneto drive gears 
are clearly outlined, while in the sectional view at the right, the ar¬ 
rangement of the fly-wheel and crankshaft assembly and the method 
of supporting it on ball bearings is outlined. The engine at Fig. 75 
is a simple T-head form with water jacket, and is a type that is used 
to some extent on light cars and cyclecars. All parts are clearly indi¬ 
cated, and in view of the explanations previously given regarding the 
duties of these parts, the reader should have no difficulty in under¬ 
standing the relation they bear to each other in the complete power 
plant, and the part they play when the engine functions. 


CHAPTER III. 


CONSTRUCTION AND DESIGN OF ENGINE PARTS. 

Methods of Cylinder Construction—Advantages of Detachable Heads— 
Material Employed and Methods of Finishing—Combustion Chamber 
Design —Relation of Valve Placing to Engine Efficiency—Bore and 
Stroke Ratio —Influence of Compression on Power Developed—Offset 
Cylinders —Automatic and Mechanical Valves—Valve Design and Con¬ 
struction —How Valves are Operated—Valve Timing—Pistons and 
Rings —Wrist-Pin and Connecting Rod Arrangements—Crankshaft 
Forms and Fly-wheels—Engine Base Design and Construction—Plain 
and Anti-Friction Engine Bearings. 

Methods of Cylinder Construction. —There are two general 
designs of cylinder construction followed by motorcycle designers, 
namely, the one-piece and the two-piece types. A typical cylinder of 
the one-piece pattern is depicted at Fig. 76 in connection with the 
piston, its wrist-pin and one of the piston rings. The cylinder in 
place on a single-cylinder power plant of Spacke make is shown at 
Fig. 77, while the part sectional view at Fig. 78 shows clearly the one- 
piece construction. In the early days, before the development of 
satisfactory cylinder-head packing, and when sheet asbestos and cop¬ 
per were the only packing mediums known for obtaining a gas-tight 
joint between the cylinder and cylinder head, there was considerable 
trouble experienced due to loss of compression and power through 
leaky packings. It was found that the sheet asbestos did not have 
sufficient strength to resist the high pressure, and the sheet metal 
packings were too hard to conform to any irregularities that might 
exist in the seating between the combustion chamber and cylinder 
when these were separate castings held together by clamping bolts. 
The complaints voiced by the riders against the two-piece construc¬ 
tion led many manufacturers to cast their cylinders and valve 
chambers in one piece instead of depending upon any kind of a pack¬ 
ing, as necessary in the two-piece construction. 

145 


Construction and Design of Engine Parts 


146 


While the one-piece cylinder offers advantages of some moment, 
in reducing the liability of leakage by eliminating a packed joint, it 
has the disadvantage of rendering the piston considerably more in¬ 
accessible than was the case where the cylinder head could be removed 
from the cylinders and expose the piston top so carbon deposits could 
be removed easily without taking the cylinder off of the engine base. 
With a one-piece construction, it is, of course, necessary to remove 



Fig. 76.—One-Piece Cylinder Construction, Also Dome Head Piston, 
Wrist Pin and One of the Eccentric Piston Rings Used With It. 


the cylinder. Another advantage possessed by the detachable com¬ 
bustion head construction is that it is possible to grind the valves in 
very easily when that member is removed, as it can be taken to the 
bench and placed in a vise where it can be held secure^ and worked 
on to advantage. In grinding the valves, particularly the exhaust, in 
most cylinders of the one-piece pattern, if one does not wish to take 
the entire cylinder assembly from the crank-case to gain access to 


















Construction and Design of Engine Parts 


147 



Fig. 77.—Exterior View of the De Luxe Single Cylinder Motorcycle 
Power Plant, Showing Practical Application of One-Piece 
Cylinder. 







148 Motorcycles , Side Cars and Cyclecars 

the cylinder from the engine, the work must be done with that 
member in place, and there is always a possibility of having some of 
the abrasive used in valve grinding find its way into the cylinder 
interior, where it would do considerable harm by causing scratches 
that run the length of the cylinder, and which interfere materially 
with retaining proper compression. Of course, it is not necessary for 
the rider to get the abrasive into the cylinder, but at the same time 
many inexperienced persons, when grinding valves, have not realized 
the importance of keeping the emery from the cylinder interior, and 
trouble has been experienced owing to unintentional neglect of this 
essential precaution. 

The inlet valve of most motorcycle engines is carried in an easily 
detachable cage which incorporates the valve seat, and it is, therefore, 
easy to grind this member at the bench. There are cylinder forms, 
however, of the T or L design where both inlet and exhaust valves 
seat directly in the valve chamber. In cases of this kind there would, 
of course, be just as much liability of emery getting into the cylinder 
while grinding the inlet valve as when fitting the exhaust member. 
The one-piece cylinder construction has the material advantage of 
considerably simplifying the motor construction as it eliminates the 
extra piece or casting that is necessary if the combustion chamber is 
separate from the cylinder. 

Advantages of Detachable Cylinder Heads.—The sectional 
view of the engine depicted at Fig. 79 shows clearly the construction 
of a detachable head and the method of holding it in place on the 
cylinder casting. It will be observed that the cylinder head not only 
includes the combustion chamber but also incorporates the extension 
in which the valves are located. The cylinder is a simple ribbed 
cylindrical member which can be easily handled in casting and ma¬ 
chining. It is held in place against a seating on the engine base by 
long bolts or studs which screw into the crank-case at the lower end, 
and which have nuts at the upper end to clamp the detachable head 
firmly in place. In the engine shown, three bolts are used, but owing 
to their disposition but one of the bolts shows in this view. It will 
be evident that the cylinder acts as a spacer between the detachable 
head and the crank-case, and that the retention bolts serve to draw 
the head and crank-case together, thus clamping the cylinder firmly 


Construction and Design of Engine Parts 


149 



in place. The two-piece construction is quite practical at the present 
time because great improvements have been made in the construction 
of gaskets or packings. 

The sheet asbestos formerly used had the advantage of being com¬ 
pressible and thus forming a very good packing, though the light rings 
of this soft material were very fragile and could not be used more than 
once, as they were invariably destroyed when the cylinder head was 

















































































































































150 


Motorcycles , Side Cars and Cyclecars 


removed from the cylinder. The hard copper did not bed itself 
properly, and unless the retaining bolts were tightened down prac¬ 
tically the same at the three points on the cylinder head there was 
very apt to be a compression and explosion leak because the inflexible 
material did not permit the head to bear down against the gasket 
resting on the cylinder. As both forms of packing had their merits, 
it occurred to some designers to try a combination of the two materials 
and a gasket or packing ring was evolved that consisted of sheet 
asbestos ring enclosed in a shell of very light sheet copper or brass. 
The metal held the asbestos in place firmly and provided an item of 
strength that was desirable. At the other hand, the light gauge of 
the copper used did not interfere materially with the flexible proper¬ 
ties of the asbestos, and the gasket readily conformed to any slight 
irregularity or roughness on the cylinder or cylinder head seat. This 
form of gasket practically eliminated the troubles which were present 
in the old detachable head engine, and many designers continued to 
use the two-piece construction. 

In addition to the big feature of providing a degree of accessibility to 
the piston top and combustion chamber interior for removing carbon 
deposits without dismantling the entire engine, there was retained the 
added advantage of having a cylinder head available that permitted 
grinding in the exhaust valves without danger of abrasive matter 
getting into the cylinder. Another feature of merit in connection 
with the detachable head construction is that cylinder replacements 
are less expensive than is the case when a one-piece cylinder is em¬ 
ployed. As will be evident, practically all of the depreciation will 
exist at that portion of the cylinder that is traversed by the piston. 
Therefore, with the one-piece construction when the cylinder became 
worn to a point where it was desirable to replace it because the thin¬ 
ness of the metal in most motorcycle cylinders does not permit of re¬ 
boring or grinding to remove deep scratches, it was necessary to throw 
away a perfectly good combustion head and valve seatings, which had 
depreciated but slightly in service. With the detachable cylinder 
construction if that member wears it can be cheaply renewed, and 
the combustion head can be used just as well with the new cylinder 
as with the old one. It is also possible to machine the interior of the 
combustion chamber more easily with the separable head con- 


Construction and Design of Engine Parts 


151 


\}edachaV>\e 
Head 


C\|Vmder 
Head Reta>W\nd 
£>o\ts 


G^Vmdev 


Cravd^casef 


C\ywV*ee\ 


tAawx SYia^t 




~\ft\efc\j&tae 
-\x\\e\. \ja\ye 

Exhaust 

MaWe 


Exhaust 

Sp rin<g 

CounecUnd 
fted 1 



Cam Gear Case 


j\Wu\g Cxear 


Fig. 79.—Sectional View of Single Cylinder Motor of English Design 

Using Detachable Cylinder Head. 





























































































































152 


Motorcycles , Cars and Cyclecars 


struction. This is a feature of some importance, especially in over¬ 
head valve types. 

Materials Employed and Method of Finishing.— Cylinders are 
invariably made of close grain gray iron which contains considerably 
more phosphorus than is usually found in the ordinary grades of cast 
iron because the metal must be capable of flowing readily and filling 
the mould. It would be rather difficult to use the ordinary casting 
metal because it would not flow readily into the small spaces left in 
the sand when the flanges are moulded, but the metal containing 
phosphorus in larger proportions fills these spaces completely, and 
makes it possible to obtain cylinder castings with perfectly formed 
cooling flanges. Some of the cast irons used in cylinder construction 
also contain some tungsten, and this alloying element produces an 
iron that has a high degree of resistance to heat. 

The common method of finishing cylinders of the simple form, i. e., 
without a cylinder head is to bore these out with a roughing cut and 
then to anneal the castings and allow them to age for a time before 
the finishing processes take place. The reason for the annealing and 
aging is to remove any internal stresses that may have been left in 
the cylinder casting when the moulten metal cooled, and usually re¬ 
moving the scale as is done by the roughing cut, permits the cylinders 
to distort appreciably. If the finishing process is continued right 
after the rough boring without the annealing, just as soon as the 
cylinder was put in service it would be apt to distort sufficiently under 
the high heat to produce some friction between the piston and 
cylinder walls. In annealing the cylinders, they are placed in a furnace 
and heated to a high’er temperature than will ever be produced by 
the explosions after they are in service. This tends to not only relieve 
the strains produced in casting but after the cylinders are cooled they 
have distorted as much as they ever will. The aging process is a 
simple one as it consists of allowing the cylinders to remain undis¬ 
turbed after they cool for several weeks. 

There are two methods of finishing the cylinders followed by most 
engine builders. One of these consists in taking a finishing cut or of 
removing enough metal from the cylinder bore, so the size is very close 
to standard, after which the remaining metal is removed by reaming. 
The other method is to grind out the surplus metal by high speed 


Construction and Design of Engine Parts 


153 


emery wheels mounted on a spindle that is adapted to traverse the 
length of the cylinder. Those who favor reaming contend that the 
grinding process will deposit small particles of emery in the open 
pores of the cast iron, and that this material is only dislodged after 
the engine is placed in service, at which time it will cause trouble by 
producing scratches on the cylinder walls. Those who favor grinding 
contend that the reaming process does not produce as true and smooth 
a bore as grinding, because if a reamer blade strikes a hard spot in the 
metal of the cylinder wall it will spring away from the hard portion 
and cut a little deeper than it should in the softer portions opposite. 
Some makers follow the reaming process with a lapping operation, 
which is done by revolving the cylinder in a suitable fixture, and at 
the same time having a dummy piston made of some soft metal, 
charged with abrasive and oil, reciprocate rapidly up and down in 
the cylinder while it revolves. Engines that have the cylinders 
finished by the lapping process do not need to be run in as long on 
the block as those in which the cylinders are either reamed or ground 
to a standard size. 

Combustion Chamber Design. —One of the important con¬ 
siderations in the design of the internal combustion motor, and one 
that has material bearing on its efficiency, is the shape of the com¬ 
bustion chamber, and this is especially true of the air-cooled forms 
of cylinders which operate at considerably higher temperatures than 
the water-cooled forms. The endeavor is made to use a form of 
combustion chamber that will provide for the least heat loss, and that 
will not interfere with a balanced design of a cylinder. Theoretically, 
any cylinders having pockets at the side to hold the valves are not as 
desirable as those forms in which the valves are placed directly in 
the head, and where the cylinder is uniform in diameter at all points. 
It is contended by designers favoring valve-in-the-head location that 
the expansion and contraction of the cylinder will be uniform because 
. the metal is evenly distributed whereas on most patterns, having ex¬ 
tensions at the side, the irregular placing of the metal will mean that 
one portion of the cylinder becomes hotter than the other part, and 
as it will not cool as fast, the cylinder will not expand and contract 
evenly at all points. The greater the amount of metal to be heated, 
the more the heat loss and the less efficient the engine. The im- 


154 


Motorcycles , Side Cars and, Cyclecars 



















































































Construction and Design of Engine Parts 155 

portant factor that has to do with the form of the combustion 
chamber used is that of valve placing, and there is considerable di¬ 
versity in practice as relates to location of the members that control 
the ingress and egress of gas to or from the cylinders. 

Relation of Valve Placing to Engine Efficiency. —The funda¬ 
mental consideration that determines valve location is that the gas 
be admitted to the cylinder as quickly as the speed demands, and 
that after it has been properly compacted and exploded that the 
inert products of combustion should be exhausted or discharged from 
the cylinder with as little back pressure as possible. While this is 
an imperative condition if one is to obtain satisfactory operation from 
any type of gasoline engine, either air or water-cooled, imperfect 
operation of the valves will be manifested much sooner in the small 
high-speed air-cooled motorcycle power plants. For example, if the 
form of. the combustion chamber is such that the entrance of fresh 
gas is impeded, the cylinder will not fill thoroughly with mixture at 
high speeds, whereas if the exhaust gas flow is impeded to any extent 
a part of the burnt gases will be retained in the cylinder, and these 
will reduce efficiency by diluting the fresh charge and making it 
slower burning, and thus cause lost power and overheating. 

Another factor that has a decided bearing upon the rotative speeds 
of small internal combustion engines is the sizes of the valves, and 
some valve locations permit the use of larger valves than do other 
positions. As will be seen by reference to illustrations, Figs. 80 to 85, 
inclusive, there are many ways of installing the valves, and that each 
method outlined must possess some points of merit is best proven 
by the fact that practically all of the forms illustrated are used by 
reputable manufacturers of motorcycles. 

The valve in the head system, which is shown in two forms at Fig. 
80, possesses important advantages from a theoretical point of view, 
and actual performance has indicated that it is a very desirable form 
of construction. When the valves are placed directly in the head, 
the inflow is direct, and the discharge is obtained with minimum back 
pressure. The inside of the combustion chamber may be machined, 
making a very good construction for an air-cooled cylinder. The 
cylinder casting is simple, and large valves may be employed which 
can be easily removed if either the cage or the removable head con- 


156 


Motorcycles , Side Cars and Cyclecars 


struction are used. The machined combustion chamber is advan¬ 
tageous for several reasons, one of the most important of which is 
that there are no sharp edges or corners to become hot and cause 
pre-ignition of the charge, and it is also difficult for carbon deposits 
to lodge on perfectly smooth machined surfaces. The combustion 



Fig. 81.—The Precision Twin Cylinder Valve-in-the-Head Motorcycle 

or Cyclecar Power Plant. 


chamber is uniform in shape, and expansion will be even when the 
cylinder is heated. 

When the valves are placed in the head there are two main methods 
of construction followed. In one of these, the head casting is remov¬ 
able, and the valves seat directly in that member. In the other con¬ 
struction, the valves are carried in cages inserted into openings pro- 











Construction and Design of Engine Parts 157 


vided for their reception when the cylinder is a one-piece member. 
The valve-in-the-head motor shown at Fig. 81 is the same as that 
outlined in section at Fig. 80, and the method of operating the valves 
when at the top of the cylinder may be readily understood. The 
valves are not always placed with the stems vertical, so that they are 



Fig. 82.—Unconventional Arrangement of Valves in the Precision 

Junior Motorcycle Power Plant. 

pushed down by rocker arms when it is desired to admit gas into the 
cylinder or to open a port for its discharge, as in some cases the valves 
are placed with their stems horizontal as shown at Figs. 82 and 83. 
The former shows a light English power plant in which the valves 
seat directly in the cylinder head. They are actuated by long rocker 
















































































158 



CxWrstVaWe 


£jx\\fcust. 

Operatv 

fte'\\ OtauK i 




SparK rW 


\n\et \!a\\ie 


InWtVaWe 
^>e\\ Cra’nK 


Tension Poci 
Ca'e'ou'reA.o'r 


Tvnirvo Gear 


Frame MemW 


Motorcycles , Side Cars and Cycle cars 


Fig. 83._An Unconventional American Motorcycle Power Plant of 

Early Design in Which the Horizontal Valves Open Directly Into 
a Vertical Combustion Chamber. 

arms fulcrumed at approximately their central point, and have a roll 
at the lower end to follow cam profiles, while an adjustable set screw 
at the upper end imparts motion to the horizontal valve stem. The 
valves may be readily exposed for grinding by removing the valve 






















Construction and Design of Engine Parts 159 


cap at the front of the cylinder. The valves are placed side by side, 
and both are mechanically operated. 

The peculiar method of valve placing shown at Fig. 83 was used 
with some degree of success on one of the earlier American motor¬ 
cycles known as the Royal. In this, the valves were carried in cages 
that bolted to an extension from the top of the cylinder that formed 
a narrow combustion chamber. The valves were placed horizontally, 
and were operated by bell cranks pivoted on the valve cage extension, 
and these were actuated by tension rods instead of the usual form of 
compression or push rod. The valves were opened by a downward 
movement or pull of the rod instead of by an upward motion as is 
now conventional practice. The engine described proved very satis¬ 
factory in practical service, and many machines were made using this 
unconventional power plant before the manufacture of these machines 
was discontinued. 

The usual arrangement of the valves is as depicted at Figs. 84 and 
85. In this system, which is the oldest in use, as it was originated by 
Daimler, the inlet valve is located directly above the exhaust member, 
and is usually carried in a valve cage held in place by a suitable dome 
or other retaining means. The dome on the Indian motor, which is 
shown at Fig. 85, is secured in place by an ingenious bayonet lock 
arrangement so it can be easily removed by moving it over from the 
position shown about half a turn and lifting it out. The form of com¬ 
bustion chamber made possible has considerable merit, especially in 
air-cooled motors, as the fresh, cool gases from the carburetor strike 
the exhaust valve head, and have a very beneficial effect as they assist 
in reducing the temperature and by preventing the valve head from 
overheating, the valve or its seating is not so apt to warp and pit as 
would be the case if it were not adequately cooled. The inlet valve 
may be of either the automatic or mechanically operated type, though, 
at the present time, practically all inlet valves are actuated by positive 
mechanical means. The cylinder is an easy form to machine, and the 
casting, even when the combustion chamber is integral with the 
cylinder, is not a difficult one to make. 

One of the disadvantages of this construction is that if large valves 
are employed, the pocket must be of corresponding size, and con¬ 
siderable heat loss will result, due to the irregular form of the com- 


160 


Motorcycles , Side Cars and Cycle cars 



Fig. 84.—One-Piece Motorcycle Cylinder, Showing the Valve Arrange¬ 
ment Generally Employed. 


bustion chamber. The gases cannot be discharged as directly as when 
the valves are placed in the head, as there is a sharp corner that must 
be turned whether the gas is flowing in or out of the cylinder. This 
feature is not one that is of sufficient importance to be advanced as 
a positive disadvantage, because so many of the very efficient motor¬ 
cycle power plants have the valves arranged in the manner shown 


















































Construction and Design of Engine Parts 101 

that the practicability of this arrangement cannot be questioned. It 
is customary, when the valves are arranged in the manner described, 
to locate the spark plugs in the side of the combustion chamber so the 
points or electrodes will be swept by the incoming gases. This tends 
to keep the temperature down and to keep them free of oil to some 
extent. 

The form of cylinder shown at Fig. 88 is known as the L-cylinder, 
because of its shape. The valves are side by side and are located in 
a common extension from the combustion chamber, and in multiple 
cylinder tandem forms, it is possible to operate all valves from a com¬ 
mon single cam shaft. The valve chamber is closed by threaded plugs 
at the top, and the valves may be easily reached by removing these 
members. A very simple valve-operating system is possible, and the 
springs and valve adjustments are easily reached when desired. The 
chief disadvantage advanced against this form of cylinder is that a 
very large pocket is necessary unless the valves are restricted in size. 
If considered from a purely theoretical point of view, this form of 
cylinder has the same disadvantages as the T-head form, in which 
the valves are placed at opposite sides of the cylinder, each in a 
separate extension, though to a somewhat lesser degree. The com¬ 
bustion chamber form that is most effective is that in which the valves 
are placed directly in the head, and next in order comes that shown 
at Fig. 85, in which the valves are placed one above the other with 
the extension of just the size necessary for the one valve. In the 
form in which the valves are placed side by side the efficiency is a little 
greater than in the T-head form, where the combustion chamber is 
of a shape that permits of considerable heat loss. 

The T-head construction has an important advantage in that 
large valves can be used, and a better balanced cylinder casting is 
possible than if the L-head construction is used. There are two valve 
chambers, usually of equal size, so the expansion is apt to be more 
uniform when the cylinder is heated than in those constructions hav¬ 
ing a valve chamber at but one side of the cylinder. Wherever the 
pocket construction is used, in addition to heat loss and the uneven 
cylinder expansion, it must be obvious that the passage of the gases 
will be impeded to some extent. For instance, consider a cylinder 
of the L form. When the piston goes down on its suction stroke, the 


162 


Motorcycles , Side Cars and Cycle cars 



Inlet 
Dome 

Inlet Valve 
t&oe 

Inkev 

Spvino 

In\etVa\| 


VaYve 

fWKet 


Cylinder 
He&d 


txKasust Valve 
^alve Stem Giuide 


Valve $p 


rm 


VaWe Stem 


Fig 85—Detachable Combustion Head of the Indian Motor With 
Valve Chamber in Section to Show Arrangement of Intake and 
Exhaust Valves. 















Construction and Design of Engine Parts 163 

inlet gases rushing in through the open inlet valve will impinge them¬ 
selves sharply upon the valve cap, and then the direction of flow 
changes abruptly at a sharp angle to permit the gases to enter the 
cylinder. The same applies to the exhaust gas, except that the direc¬ 
tion of flow is reversed. W hen the valve-in-the-head type of cylinder 
is employed the only resistance offered to the passage of the gas is 



struction. 


in the manifold, and if these are properly proportioned the velocity 
of gas flow will not be reduced much. Experience has shown that a 
valve-in-the-head motor is more flexible and responsive than the other 
forms, and in most cases it will be somewhat more efficient and de¬ 
liver more power than others of the L or T form that have the same 
piston displacement. 






















































































104 


Motorcycles , Side Cars and Cyclecars 


Bore and Stroke Ratio.- —A question that has created consider¬ 
able discussion among automobile engineers is the proper relation of 
the bore to the stroke, and recent developments indicate that long- 
stroke motors, which are those forms where the piston travel is 1.5 
or 1.75 times the diameter of the cylinder bore, have many ad¬ 
vantages to commend them. While the long stroke principle is well 
adapted to motors designed for low and moderate speed, it is not 
suited as well for the small high-speed motors used as motorcycle 
power plants. The stroke seldom exceeds the bore by any material 
amount, and the usual ratio is 1 to 1.25. For example, an engine 
with a 3.5-inch bore would not be likely to have more than 4-inch 
stroke. The reason that the length of the stroke or the amount of 
piston travel does not exceed the diameter of the bore by any great 
amount is the endeavor to keep within proper limits as regards piston 
speed. 

In an air-cooled motor, the question of lubrication is the main 
governing factor, which determines the velocity of piston motion, and 
the greater its speed, the more difficulty there is in securing proper 
oiling of the reciprocating member. Most automobile engineers en¬ 
deavor to keep the piston speed to about 1,000 feet per minute, though 
in motorcycle engines satisfactory service is obtained with piston 
speeds as high as 1,200 feet per minute in machines built for road 
work and even higher if the engines are designed with the require¬ 
ments of racing service in mind. 

Let us consider what is meant by piston speed and how this in¬ 
fluences the number of revolutions possible. Assume that we have an 
engine with a stroke of 6 inches, it is evident that during 2 strokes 
the piston will have covered a distance of 1 foot. As there are 2 
strokes per revolution of the fly-wheel or crankshaft, it will be seen 
that a normal speed of 1,000 revolutions per minute is permissible 
for an engine with a 6-inch stroke without exceeding the limits estab¬ 
lished by engineers. If the piston had a stroke of 4 inches, 1,500 
revolutions would mean a piston travel of 1,000 feet per minute, and 
with a 3-inch stroke, the safe speed of 1,000 feet would not be ex¬ 
ceeded if the engine crankshaft revolved 2,000 times per minute. 
There is no arbitrary rule that can be cited as establishing the factor 
of piston speed or relation of bore to stroke definitely and in races, 


Construction and Design of Engine Parts 


165 


engines have been used where the piston speed was over twice that 
considered good practice. 

Influence of Compression on Power Developed. —The relation 
of compression ratio to the amount of power obtained when the charge 
of gas is exploded is such that more power is obtained with high com¬ 
pression than where the gas is not compacted to such a degree. With 
water-cooled engines, such as used in general automobile practice and 
a few motorcycles, it is possible to use higher compressions which mean 
a smaller combustion chamber in relation to the volume swept by the 
piston than is permissible with air-cooled engines. This is because 
more heat is developed with a high compression prior to ignition and 
it is possible to compress the gas to a point where the engine would 
overheat rapidly owing to the limitations of the air-cooling system. 
An engine with a high compression is not so well adapted for general 
service as one with a medium compression because the engine will 
not be as flexible or operate as smoothly under normal service con¬ 
ditions. The general practice in motorcycle engines intended for road 
use is to use a compression pressure of about 60 pounds gauge indica¬ 
tion which means that the gas in the cylinder and combustion chamber 
is compressed to about one-fourth the volume it occupies before it is 
compacted. In an air-cooled motor, if the compression pressure ex¬ 
ceeds 75 or 80 pounds, the engine will heat up rapidly and the cylinder 
head will soon become hot enough to fire the gas without the aid of 
the electric spark. This results in pounding, and while the engine is 
more powerful than a type with lower compression, it cannot be 
used for any extended periods without incurring the danger of pre¬ 
ignition. 

The following table shows the maximum explosion pressure, in 
pounds per square inch, obtained with various degrees of compression. 
In this case, the compression ratio means the volume the gas occupies 
after compression based on an initial pressure of about 15 pounds 
per square inch, which is that present in the cylinder when the piston 
reaches the end of its suction stroke, and when the cylinder is full of 
gas, and, therefore, has the same pressure as the atmosphere. A com¬ 
pression ratio of 3 means about 45 pounds compression. A ratio of 
4 about 60 pounds, etc. The actual amount of compression is not the 
pressure that one would obtain by multiplying the atmospheric pres- 


166 


Motorcycles , Side Cars and Cyclecars 


sure directly by the ratio of reduction in volume because compressing 
the charge increases the temperature, and this in turn produces an 
increase in pressure so that the actual compression is somewhat higher 
than would be obtained by a simple calculation. This variation is 
not sufficiently great however, so that it must be considered at length 
in a practical discussion; so we will assume, in comparing the results 
of the table appended, that the compression pressure is that of the 
atmosphere multiplied by the compression ratio indicated. 

MAXIMUM EXPLOSION PRESSURE. 


Compression Ratio. 

Maximum Explosion Pressure 
(Pounds per square inch) 

3 

230 

3.2 

250 

3.4 

274 

3.6 

298 

3.8 

321 

4.0 

344 

4.2 

368 

4.4 

392 

4.6 

414 

4.8 

437 

5.0 

460 


It will be evident that as the compression increases, the amount of 
pressure obtained when the charge is exploded augments as well, and 
that if there were no other consideration involved, the engine with 
the highest compression would give the most power. 

Offset Cylinders. —In some constructions, the cylinder is placed 
on the engine base so its center line is to one side of the center line of 
the crankshaft, and diagrams are presented at Fig. 86 which make 
clear the advantages obtained by this method of cylinder placing. 
The view at A is a section through a simple motor having the con¬ 
ventional cylinder arrangement and the center-lines of both crank¬ 
shaft and cylinder coincide. The sectional view at B shows the 








Construction and Design of Engine Parts 


167 


cylinder placed to one side of center so its center line is distinct from 
that of the crankshaft and at some distance from it. The amount of 
offset to be allowed is a point upon which considerable difference of 
opinion exists, the usual offset being from 15 to 25 per cent, of the 
stroke. 

The advantages of the offset are shown at C and D. If the crank¬ 
shaft turns in the direction of the arrow, there is a certain resistance 
to motion proportional to the resistance offered by the load which is 
always less than the amount of energy exerted by the engine as long 
as the vehicle is in motion. There are two thrusts acting against the 
cylinder wall to be considered, one of these due to the expansion of 
the gas against the piston top and the other being produced by the 
force that resists the motion of the piston. These thrusts may be 
represented by arrows, one of which acts directly in a vertical direc¬ 
tion on the piston top, the other on a straight line through the center 
of the connecting rod. Between these two thrusts, a third line may 
be drawn to represent a resultant force that serves to bring the piston 
in forcible contact with one side of the cylinder wall. This angular 
resultant is generally termed “side thrust.” In the engine shown at 
C which is one in which the center line of cylinder and crankshaft 
coincide, the crankshaft is at 90 degrees or about one-half stroke, and 
the connecting rod is at approximately 20 degrees angle. A shorter 
connecting rod would increase the diagonal resultant and side thrust, 
while a longer one would reduce the angle of the connecting rod, and 
correspondingly diminish the side thrust. With an offset construction 
depicted at D, it will be noted that the same connecting rod length 
as shown at C, and with the crankshaft in the same position, the con¬ 
necting rod angle is but 14 degrees, and the side thrust is reduced 
proportionately. 

Another important advantage is that greater efficiency is obtained 
from the explosion with an offset crankshaft, because the crank-pin 
is already inclined when the piston is at top center, and all of the 
energy imparted to the piston by the explosion may be utilized 
directly and will produce a useful turning effort. With the cylinder 
placed directly on a line with the crankshaft, as shown at A, some of 
the force produced by the explosion will be exerted in a straight line, 
and until the crank moves, the pressure that might be employed in 


168 Motorcycles , Side Cars and Cyclecars 

obtaining useful turning effort is wasted by producing a direct pressure 
upon the lower half of the main bearing and the upper half of the 
crank-pin bushing. If one will compare the illustrations at E and F, 
this important advantage offered by the offset construction may be 
readily understood. This shows a bicycle crank hanger, and it is ap¬ 
parent that the effort of the rider is not as well applied when the 
crank is at position E as when it is at position F. In fact, practically 
all riders instinctively place the pedal as shown at F when starting 
out, because it is much easier to start the bicycle under these con¬ 
ditions than when the crank is straight up and down. Apparently, 
position E corresponds to the construction shown at A where the 
cylinder and crankshaft centers coincide, while that at F is com¬ 
parable to the conditions present when an offset cylinder is employed. 

It is advanced by those who do not favor the offset cylinder placing 
that while side thrust is diminished on the explosion stroke it becomes 
greater than in the other constructi on on the compression and exhaust 
strokes. This is true, but it would seem to the writer that it is more 
desirable to reduce side thrust under conditions where the maximum 
pressure is exerted against the piston top, as obtains during the ex¬ 
plosion stroke, even if a little sacrifice is made on the upstroke against 
the much lighter pressures that are present on the compression or 
exhaust stroke. 

Automatic and Mechanical Valves. —The first motorcycle en¬ 
gines evolved, as was also true of the early forms of automobile 
motors, had but one of the valves in each cylinder operated by 
mechanical means. The inlet valves could be controlled by the suc¬ 
tion of the piston as it descended on its inlet stroke, because the differ¬ 
ence in pressure between the cylinder interior and that of the outside 
air was such that a partial vacuum existed in the cylinder, and as the 
valve head had more pressure on its upper side than on that adjacent 
to the combustion chamber it would, of course, open automatically. 
The spring on the valve stem needed only to be heavy enough to 
return the valve to its seat at the end of the inlet stroke. When the 
pressures above and below the valve heads had become equalized 
through the cylinder filling with fresh gas, it was approximately at 
atmospheric pressure at the end of the stroke. When the piston 
started to go up on the compression stroke, the pressure of the gases 


Construction and Design of Engine Carts 


169 




Fig. 87.—Sectional Views of Peugeot Motor, Showing Automatic Inlet Valves. 


























































































































170 Motorcycles , Side Cars and Cyclecars 

increased from that of the atmosphere to three and five times this 
value when the piston had reached the end of its upward movement. 
This compressed gas and the explosion that followed as well as the 
pressure in the cylinder during the exhaust stroke were always greater 
than that of the atmosphere, so the inlet valves remained seated, and 

only opened when there was a 
partial vacuum in the cylinder. 

The automatic valve had an 
important advantage and that 
was its simplicity, as it did not 
require any external operating 
mechanism. At the other hand, 
a motor fitted with automatic 
inlet valves was not as satisfac¬ 
tory, after it had been in service 
for a time, as the form in which 
the inlets were actuated mechan¬ 
ically. Automatic valves were 
apt to flutter at low engine 
speeds, and were not only noisy 
but also prevented drawing in a 
full charge of gas into the cyl¬ 
inders. Accumulations of con¬ 
gealed oil or carbon between the 
valve head and seat would tend 
to make these members stick, 
which would prevent prompt 
starting as well as making the 
valve late in opening. The light 
springs that were employed to 
reseat the valves did not have 
pressure enough to crush any small particles of carbon that lodged 
between the valve head and its seat, and, as a result, the automatic 
valve was apt to leak on the slightest provocation. On twin-cylinder 
engines used for motorcycles or on the four-cylinder types adapted 
for automobiles, the use of automatic valves did not conduce to 
smooth running because the only way of insuring that each cylinder 



Fig. 88.—Sectional View of L Head 
Cylinder, Showing Arrange¬ 
ment of Valves When Dupli¬ 
cate Members are Used for 
Inlet and Exhaust Port Con¬ 
trol. 













































171 


Construction and Design of Engine Parts 

would receive the same amount of gas was to carefully go over the 
inlet valves periodically to see that the tension of all the springs was 
the same; that each valve opened the same amount, and that all were 
properly cleaned. If one cylinder was lubricated more than the 
others, the valve in that member was apt to stick while the others 
would function properly. There was no uncertainty regarding ex¬ 
haust valve operation because these members have, of necessity, al¬ 
ways been actuated mechanically, so after rather unsatisfactory ex¬ 
periences with the automatic inlet valve, motorcycle engine designers 
decided to operate both valves mechanically. 

The mechanical valve is positive in action, the spring used to return 
it to its seat can be made strong enough so that this function is per¬ 
formed correctly several thousand times per minute, and the valve is 
not susceptible to sticking owing to accumulations of oil or to remain 
open either partially or completely because of the interposition of 
some minute piece of foreign matter between the valve head and its 
seating. A typical motorcycle power plant of the twin-cylinder form, 
in which automatic inlet valves are employed, is depicted at Fig. 87. 
Attention is called to the inlet valve depressors mounted at the top 
of the inlet valve cages A. These were used to open the valves when 
starting the motor to make sure that they were free, and not stuck 
to the seat. The sectional view of the valve chamber depicted at 
Fig. 88 shows one application of mechanical valves, and in this form 
it will be apparent that the valves are duplicates, which means that 
the intake and exhaust valves are interchangeable, and only one spare 
valve need be carried as a replacement. 

Valve Design and Construction.—One of the most important 
considerations in valve design is to have these of ample size, and 
many factors are to be considered before the size can be determined. 
Among these may be stated the location in the cylinder, the method 
of operation, the material employed, the degree of lift or free opening 
desired, the speed of rotation of the engine, and the method of cooling 
the engine cjdinder. It will be apparent from our review of the various 
possible valve locations that if these members are placed directly in 
the cylinder head, we are not only able to obtain an ideal com¬ 
bustion chamber form but we can also use valves of fairly large 
size. The method of operation also has some bearing on the size of 


172 Motorcycles , Side Cars and Cyclecars 

the valves. For example, when automatic inlet valves were used, it 
was the general practice to obtain the required area of valve opening 
by using valves of large diameter, but with less lift or movement than 
is ordinarily allowed for mechanical valves. For this reason, auto¬ 
matic valves were 15 to 20 per cent, larger in diameter than mechanic¬ 
ally operated members. When both valves are mechanically operated, 



Fig. 89.—Typical Motorcycle Valves. A—Automatic Inlet Valves. 
B—Usual Construction of Exhaust Valves. 


it is an advantage of some moment if they are made of the same size 
and interchangeable, as this not only greatly simplifies manufacture 
but is appreciated equally well by the rider if replacements are 
necessary. 

The relation of the valve diameter to the cylinder bore is one upon 
which considerable difference of opinion exists. The writer has al- 
































































Construction and Design of Engine Parts 173 


ways been of the opinion that, in air-cooled engines designed for high 
speed, the valves should be nearly half the diameter of the bore in 
width, whereas others do not favor diameters in excess of one-third 
the bore. The larger the area of the valve the less lift required, and 
this is an important factor where extreme speed is desired, because 
the valve is more silent in operation, and there is less wear on the 
parts. A valve with a small lift can be opened to its maximum point 
by a cam with a low profile, whereas one with a small diameter and 
requiring greater lift will, of course, require a higher cam that will be 
somewhat more abrupt in action. A large valve is more subject to 
warping than one of lesser diameter, and this is a factor that must be 
considered in connection with the design of exhaust valve. The ex¬ 
haust valve becomes very hot, especially if the engine is run with a 

% 

rich mixture and a retarded spark, and it is necessary to make these 
of materials that are not apt to be affected by heat as well as propor¬ 
tion them so the diameter and distribution of metal around the head 
will tend to prevent deformation under heating. 

The mushroom or poppet valve has become generally accepted in 
motorcycle practice, though in automobile engineering considerable 
attention is being paid to development of various types of sleeve, 
sliding ring, reciprocating piston or rotary forms of valves. The flat 
seat valve is seldom used in motorcycle practice, though it has been 
applied to some extent on automobile engines. The usual construc¬ 
tion is to use types in which the face of the valve is beveled to fit an 
angular seating. This form has important advantages, one being 
that the wedging action of the valve head in its seating not only 
tends to make a tighter seat but that it is drawn in place positively 
by the spring pressure. Even if the valve stem guide is worn appre¬ 
ciably the valve will center itself when the beveled head seats. The 
method of valve construction generally employed is to make that 
member in one piece, though formerly the head was sometimes made 
of one substance such as cast iron and riveted onto another material, 
such as a steel stem. These valves did not prove satisfactory owing 
to difficulty of keeping the head tight on the stem, as the constant 
hammering action of the valve head against the seat in combination 
with the heat caused internal stresses that produced distortion and 
loosening of the head relative to stem. 


174 


Motorcycles , Side Cars and Cyclecars 


At the present time valves are generally machined from forgings of 
alloy steel and are made in one piece, though valves in which a nickel 
steel head is electrically welded to a carbon steel stem have received 
some application. For high-speed air-cooled engines a new tungsten 
alloy steel has been adopted to some extent. While nickel steel valves 
have much higher resistance to heat than the ordinary grades of steel 
or cast iron, the tungsten alloy is unquestionably superior. Tungsten 
is extensively used in making high-speed steels for lathe tools, and in 
this service a tungsten alloy metal will retain its cutting edge even 
when brought to a red heat by the combination of heavy cuts and high 
speed. These qualities make this alloy especially well suited to air¬ 
cooled engine service, and it is contended that a properly treated 
tungsten valve will retain its toughness and resistance to deformation 
at temperatures over 500 degrees higher than those ordinarily present 
in motor cylinders. 

The two forms of valves ordinarily used are shown at Fig. 89. The 
two at the left of the illustration are inlet valves, while that at the 
right is an exhaust-port controlling member. Inlet valves are usually 
made lighter than the exhaust, especially if of the automatic form, 
and the sections can be thinner because the inlet valve is kept much 
cooler by the flow of the comparatively cool gas, whereas the exhaust 
valves are subjected to intense heat when the inert products of com¬ 
bustion are discharged as a flaming gas around them. It is good 
practice, even on inlet valves, to have a large fillet between the valve 
head and stem because this strengthens the stem at its weakest point, 
and prevents distortion of the head as well as preserving its proper 
alignment with the stem. 

The two common methods of holding the valve-spring collar in 
place are depicted. In the upper view, the valve stem is slotted, and 
a key is passed through it which is prevented from moving sideways 
by the chambered head of the valve-spring collar. As that member 
is always pressed securely against the key by the valve spring, the 
key must stay in place as long as the spring performs its functions. 
The collar of the valve in the lower portion of the illustration is held 
in place by a nut and lock nut which fit the threaded end of the valve 
stem. 

The exhaust valve, which is shown at the right of the illustration, 


Construction and Design of Engine Ports 


m 



Fig. 90.—View of Reading-Standard Single Cylinder Motor With 
Timing Gear Case Cover Removed to Show Valve Operating 
Mechanism. 


is an example of excellent valve design. The head is domed, which 
is preferable to the perfectly flat form, and it is also smooth and with¬ 
out the slotted boss shown on the inlet valves in the same illustration. 
The slotted boss is necessary on a thin valve head, because it is by 
inserting a screw driver in this that the valves are turned for grinding. 





176 


Motorcycles , Side Cars and Cyclecars 


If a slot was cut directly in a light valve head, it might weaken the 
construction to some extent. With the domed head, it is a simple 
matter to cut a screw-driver slot in the arched portion without 
weakening the head construction. The exhaust valve outlined is a 
well-proportioned one-piece valve, as there are no sharp corners to 
become heated, the head is of such shape that it will not warp, and 
the enlargement of the valve stem near the head not only has a 
tendency to deflect gases flowing in or out of the cylinder but also 
strengthens the stem at a point that is normally weak. As the ex¬ 
haust gas strikes the valve stem immediately below the head when 
that member is open, and as considerable heat is present that tends 
to scale and burn away the valve stem, especially if ordinary carbon 
steel is used, the extra metal is of great value. 

How Valves are Operated. —The method of operating the valves 
of a motorcycle engine is determined bj^ their location, and the general 
arrangement of the cams employed to raise or depress the valves, as 
the case may be. When the valves are placed side by side in the 
cylinder head, as shown at Fig. 90, it is possible to operate them by 
very simple means as all that is needed is some form of push rod or 
plunger arrangement supported by suitable guides that will be lifted 
by small levers riding on the cams, and in turn raise the valve stems 
against which they bear. 

The operation of the cam is not difficult to understand, as most 
cams consist essentially of a circle having a raised point at one portion 
of its outer circumference. All portions of the circle are, of course, 
the same radius from the center except at the point raised to fonn 
the cam. As long as the cam rider or follower rests on the circular 
portion, it will not move, because the point against which it bears 
on the cam surface is always the same distance from the cam center. 
When the raised portion of the cam comes in contact with the lever, 
it will cause that member to move, and this movement may be made 
to occur at any portion of the crankshaft or piston travel, or exactly 
when it is needed. The height of the raised portion is one of the con¬ 
tributing factors that determine the amount of valve opening, the 
others being the proportions or leverage of the cam riders and the 
adjustment of the valve plungers. 

In motorcycle engines, it is now common practice to make the cams 


Construction and Design of Engine Parts 177 

integral with the gear driving them. This gear is always driven at 
half crankshaft speed, and very often it is one of the members that 
drives the gear train that produces motion of the magneto armature. 



Fig. 91.—Part Sectional View of the Royal Enfield (English) Twin 
Motor, Showing Application of Two Separate Cam Gears, One 
for the Inlet Valves, the Lower One for Operating the Exhaust 
Members. 





178 Motorcycles , Side Cars and Cyclecars 

Sometimes two separate cams are used, each driven by its own gear. 
An example of this construction is outlined at Fig. 91. In this, the 
inlet cam and mechanism employed in actuating the inlet valves is 
mounted above the timing gear on the crankshaft while the exhaust 
cam and its driving gear is mounted below it. On the multipe- 
cylinder engines, of which the form shown at Fig. 92 is an example, 
cylinders of the T-head type are used. In this case, the inlet valve 
is mounted at one side of the cylinder and the exhaust valves are 
mounted on the other side. This means that each set of valves must 
have an independent cam-shaft driven from a common crankshaft 
gear, and that one cam must be provided on each of these shafts for 
each valve to be operated. In engines of this type, the valve-operating 
mechanism is much more direct than in other forms where there may 
be several cam riders interposed between the cam and the valve stem 
in addition to the usual valve-operating push rod. In the cylinder, 
depicted at Fig. 92, the valve-operating push rod is lifted directly by 
the cam without the interposition of any auxiliary levers, as a roll 
at the lower end of the tappet rides on the cam and, of course, follows 
the contour very accurately. This type of construction is much more 
common in automobile practice than it is on motorcycle engines, be¬ 
cause the high-speed power plants used in the latter form of vehicle 
demand an entirely different treatment as far as the method of valve 
operation is concerned than do the slower-acting automobile motors. 

For instance, where the tappet rod is actuated directly from the 
cam, there is a certain amount of side thrust present between the 
tappet and its guide all the time that the tappet roller is being raised 
by the incline on the cam profile. At high speeds, this thrust action 
is very noticeable and, as it contributes to wear, high-speed engines 
soon become noisy if the direct system of valve operation is employed. 
When a lever or cam follower is interposed between the cam and the 
valve stem, that member will be subjected to thrust instead of the 
valve-operating plunger. As an example of the direct method of valve 
operation, the cross-sectional view at Fig. 92 is excellent, and the two 
forms of operating the valves that are commonly used may be clearly 
understood by referring to Fig. 93 where they are well defined. The 
exhaust valve is operated directly by means of a plunger which bears 
upon a cam rider which is lifted by a suitable member on the cam- 


AfclveCap 


Construction and Design of Engine Parts 


170 







































































































































































































180 


Motorcycles , Side Cars and Cyclecars 


shaft below it. The upward movement of the valve-operating plunger 
results in a direct corresponding motion of the valve, which, of course, 
must be raised from its seat in order to permit the gas to flow through 
the exhaust port. The inlet valve, which must be depressed to open, 
works in a direction opposite to that of the valve plunger movement. 
While the valve plunger is being raised, the inlet valve stem must 
be depressed. This is easily accomplished by the use of a rocker 
arm or simple lever fulcrumed approximately at its center, and having 
one portion bearing against the valve stem while the ether is in con¬ 
tact with a tappet rod extending from the valve-operating plunger. 
As will be evident, an upward movement of one end of the lever will 
result in a corresponding movement in the other direction at the 
other end. 

When valves are placed directly in the head, both members are 
actuated by rocker arms and tappet rods. The view of the valve- 
operating mechanism at Fig. 94 shows a rather unconventional system 
in which face cams are used to operate the bell cranks, which, in turn, 
raise the valves. The usual form of cam has the raised portion on 
its outer periphery instead of on the face. When face cams are used, 
considerable end thrust is present on the cam-shaft; and in the engine 
shown, all end movement of the cam-shaft, due to the side thrust of 
the spiral gears employed in driving the cam-shaft or magneto or the 
side thrust against the cams, caused by the valve springs, is taken 
by a pair of ball-thrust washers which always keep the cam-shaft in 
perfect alignment, and which prevent any friction because of this 
side thrust. Plain thrust bearings in the form of hardened steel or 
fiber washers have been tried at similar points, but these have not 
proven satisfactory, because too much friction was present between 
the plain bearing faces at high engine speeds, especially where lubri¬ 
cation was not always adequate. The use of thrust bearings of the 
anti-friction type means that the cam-shaft will operate for extended 
periods without any perceptible bearing looseness. With the old 
forms of plain bearings, when these wore there was considerable end 
movement possible in the cam-shaft, and considerable strain was im¬ 
posed on the driving gears and valve-actuating mechanism. The use 
of b^ll bearings has entirely cured any trouble due to side movement 
of the shaft. This motion not only produced considerable noise by 


Construction and Design of Engine Parts 


181 



Fig. 93.—Valve Operating System and Magneto Drive of the De Luxe 
Single Cylinder Motorcycle Engine. Note Also Roller Bearings 
in Connecting Rod Big End. 

permitting the gears to grind, due to poor alignment, and also pro¬ 
moted a metallic knock due to side slap of tlie cam-shaft, but it also 
interfered with engine efficiency by altering the valve timing. 































182 


Motorcycles , Side Cars and Cyclecars 


The complete valve-operating mechanism used in the Indian motor 
is shown at Fig. 95, while the method of relieving the compression to 
permit of prompt starting is clearly outlined at Fig. 96. The inlet 



Fig. 94.—Valve Operating Arrangement of the De Luxe Twin 

Cylinder Motor. 




















Construction and Design oj Engine Parts 183 

and exhaust cams are integral and are operated by a common cam¬ 
shaft. The inlet cam followers are in the form of simple forged bell 
cranks which bear against the inlet valve lift lever in the manner 
indicated. A motion of the lower end of the bell crank will be trans¬ 
mitted to the inlet valve lift lever which bears against it. It is claimed 
for this valve-operating mechanism that the action is quiet at the 
highest engine speeds, that the system is positive in action, and that 
it is not subject to rapid depreciation. All of the bell cranks and 
valve lift levers are of hardened steel, and the entire mechanism is 



Fig. 95 .—Valve Operating Mechanism of the Indian Twin Cylinder 

Motor. 










184 


Motorcycles , Side Cars and Cyclecars 



MemWv 


Fig. 96.—Method of Raising Exhaust Valves to Relieve Compression 
in Cylinders Employed on Indian Twin Motors. 


well encased so that it will operate in oil and at the same time be kept 
clean and free from dirt. 

In order to promote easy starting in motorcycle engines, it is cus¬ 
tomary to provide some system of relieving the compression in the 
cylinders so the engine may be turned over with minimum exertion 
on the part of the rider. This is generally accomplished by partially 
raising the exhaust valves by an auxiliary actuater controlled by hand 
and independent of the usual exhaust cam. The system used on the 
Indian motor and shown at Fig. 96 is not only simple, but it is effective 
and positive as well. A thin double cam member having a series of 
teeth in the upper portion is placed between the two exhaust valve 
lift bell cranks. This may be rocked by a toothed segment connected 











185 


Construction and Design of Engine Parts 

to the grip on the handle bar. When the double cam is rocked, it will 
raise the exhaust valve lift bell crank regardless of the exhaust cam 
position, and these members, in turn, will raise the exhaust valve by 
the short exhaust valve lift levers they bear against. 

The views at Fig. 97 show a simple and effective valve-operating 
mechanism used on the Precision engines, which are of English design. 
Both of the mechanisms described are employed on single-cylinder 
engines. The view at Fig. 97, A, is of the gears assembled on the cam 
case, and it will be apparent that the engine shaft-gear is mounted 
between the inlet cam drive gear and the exhaust cam drive gear. 
The view at B, which shows the assembly in the cam case, makes 
clear the type of valve-operating bell crank and unconventional cams 
employed. These are internal instead of external forms, and they are 
formed integral with the half time or speed reduction gears. The 
valve-lifting plungers are provided with adjustments so the distance 
between the top of the plunger and the valve stem will be very closely 
regulated. 

The valve-operating mechanism at Fig. 98 is employed in another 
form of Precision engine in which the valves are placed side by side 
in an extension from the cylinders, both being of the same type and 
interchangeable. The view at A shows the appearance of the assembly 
when viewed from the front, and the method of housing the cam-gear 
case attached to the engine base. The gear used to drive the cam is 
twice the size of that on the engine shaft, and therefore drives the 
cam-shaft at one-half engine speed, as is customary. The valves are 
raised by plungers which rest on the ends of levers that carry the 
cam-riding rolls. The arrangement of these members, and form of 
cams used, are depicted at Fig. 98, B. Each of these levers is ful- 
crumed at its extreme end and carries a cam roller which follows the 
cam contour with minimum friction. 

One objection that has been advanced against valve-in-the-head 
motors, is that the overhead valve-operating mechanism was subject 
to rapid depreciation on account of the presence of grit and dirt at 
the somewhat limited bearing point on the rocker arms. In order to 
prevent the accumulation of foreign matter, some makers of motor¬ 
cycle engines are enclosing the inlet valve-gear so it is not only pro¬ 
tected from deposits of dirt but makes the engine appear considerably 


186 


Motorcycles , Side Cars and Cyclecars 




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187 


Construction and Design of Engine Parts 

simpler and actually decreases the noise. The external view of the 
twin-cylinder power plant at Fig. 99 shows the smooth appearance of 
the inlet valve-cage, while the method of closing in the rocker arm 
with a pressed steel cap held in place by two screws can be understood 
by reference to Figs. 93 and 94. 

Valve Timing. —Another important consideration that has ma¬ 
terial bearing on the power, speed and flexibility of the motorcycle 
power plant is the valve timing. It is imperative that the valves not 
only open to their full extent but also that they open in correct relation 
to the movement of the piston, in order to insure a full charge of fresh 
gas or thorough expulsion of the exhaust. In the first gas engines 
which were built to operate at low speed, the usual practice was to 
open the inlet valve just as soon as the piston started to go down on 
its suction stroke, and to open the exhaust valve when the piston had 
reached the end of its power stroke. The inlet valves were closed 
promptly at the end of the first down stroke of the piston, while the 
exhaust valve was seated just before the inlet valve opened or at the 
end of the exhaust stroke. It will be evident that the valves were 
each opened a period corresponding to one-half revolution of the fly¬ 
wheel, or 180 degrees crankshaft travel. 

In endeavoring to secure greater speed and flexibility from the 
internal combustion motor, which was imperative before it could be 
applied with any degree of success to vehicle propulsion, the de¬ 
signers, reasoning from well-established steam practice, began to con¬ 
sider giving the exhaust valves a “lead,” or to open them before the 
pistons had reached the end of the explosion stroke. As the exhaust 
gases had considerable pressure, a large portion of this residue would 
escape through the open exhaust valves before the piston had reached 
the end of its power stroke, and during the next up stroke the cylinder 
would be thoroughly cleared out by the displacement of gas, due to 
the upward movement of the piston. The control of the valve timing 
is by altering the relation the timing gears and adjustment of the 
valve-lifting push rods or tappets bear to the piston travel. 

In the engine shown at Fig. 100, the cover has been removed from 
the cam gear case so the various gears employed in operating the 
valve-lifting cams and the magneto are shown in proper relation. It 
will be observed that the timing gear is attached to the crankshaft, 



188 


Motorcycles , Side Cars and Cyclecars 



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Fig. 98.—Arrangement of Valve Operating Gear of Single Cylinder L Head Precision Motors. A—Timing 
Gear Case With Cover Removed, Showing Method of Driving Cam Gear From Crank Shaft. 
B—Outlining Cam Gear With Inlet and Exhaust Cams Integral and Design of Valve Raising 
Levers. 













Construction and Design of Engine Parts 180 

and that this meshes with cam gears, one of these being employed for 
each cylinder. In timing the motor after the adj ustment of the gears 
has been disturbed it is necessary to place the distinguishing marks 
on the various gears as indicated in the illustration. One gear is 


Pig. 99 ._The De Luxe Twin Cylinder Motorcycle Power Plant With 

Enclosed Inlet Valve Operating Gear. 







190 


Motorcycles, Side Cars and Cycle cars 


marked F and has an arrow pointing to one of the teeth immediately 
under the letter. The other cam gear is marked R, and has a similar 
arrow extended to the gear teeth. The cam and gear assembly 
marked F is employed for the front cylinder, that marked R is utilized 
for the rear cylinder. Two arrows are placed on the crankshaft gear, 
and to secure proper valve timing it is required that the cam gears 
be replaced so the arrows on the side will register with those on the 
crankshaft gear. An arrow is also marked on the magneto-drive gear, 
and when the arrows on the timing gears are in proper register, that 
on the magneto gear should coincide with a corresponding mark on 
the timing gear case. The idler or intermediate gears may be replaced 
without any regard to the way they are meshed, as these will not 
affect the timing provided that the remainder of the gears are in 
proper relation to the marks provided as an index for proper resetting. 

The view at Fig. 101, which represents a single-cylinder engine with 
one-half of the cylinder and crank-case removed, shows the position 
of the piston when the exhaust valve is about to open, and the sec¬ 
tional view through the valve chamber shows the exhaust valve still 
seated, but its operating mechanism which is indicated in the timing 
gear case is just about to ride on the point of the cam and open the 
valve. The exhaust valve in this specific instance opens when the 
piston is about 7 /16 of an inch away from the bottom of the cylinder, 
measuring from that point to the bottom of the piston. In this case, 
the exhaust valve starts to open when the crankshaft has traveled 
135 degrees from the position at the time the gas was ignited, and 
the crank-pin must cover an arc of 45 degrees before the fly-wheel 
will have completed the half revolution corresponding to the down¬ 
ward travel of the piston during the expansion stroke. The exhaust 
valve should close when the crank-pin has traveled a distance of 193 
degrees on the exhaust stroke, which means that the crank will have 
reached its top center and the piston has started to go down again 
a distance corresponding to 13 degrees movement of the crank-pin. 
This represents a downward movement of the piston of but 1 /16 of 
an inch. Just as soon as the exhaust valve closes, the inlet valve 
opens as shown at Fig. 102. The inlet valve remains open a period 
corresponding to 10 to 20 degrees movement of the crank-pin after 
the piston has reached the bottom of the suction stroke, or has covered 


191 


Construction and Design of Engine Parts 

approximately 3 /32 of an inch upward movement on the compression 
stroke. 

The actual duration of the exhaust period is therefore the sum of 
45 degrees and 193 degrees, or 238 degrees. The inlet valve remains 
open a period corresponding to 180 to 190 degrees crank-pin travel. 



Fig. 100.—Reading-Standard Twin Cylinder Motor With Cover 
Removed From Timing Gearcase to Show Designs of Cams and 
Marks on Gears to Indicate Correct Setting as Determined by the 
Factory. 

The reason that the inlet valve is allowed to lag and that the exhaust 
valve does not close exactly on center is that the gas has acquired 
a certain degree of momentum during the upward stroke of the piston, 
and this may be taken advantage of in securing more thorough charg- 






192 Motorcycles , Swfe CWs and Cyclecars 

ing or scavenging if the valve remains open for a time after the piston 
reaches the top of its stroke. The exact duration of the inlet and 
exhaust periods depends upon a number of factors, and will vary in 
practically all engines by a few degrees crank-pin travel. 

It is generally recognized, however, that it is imperative to open 
the exhaust valve early if high speed and efficiency are to be obtained, 


Fig. 101.—Sectional View Showing Point in Crank Pin Travel at 
Which Exhaust Valve Opens on Thiem Single Cylinder Motor. 

and that some benefit is derived by deferring the opening of the inlet 
valve until a condition of partial vacuum exists in the cylinder. If 
the inlet valve opens late, the gas will tend to rush into the cylinder 
faster than would be the case if it opened just after the piston had 
reached the top of its scavenging stroke. The valve opening may be 
varied very accurately by suitable adjusting members on the valve- ' 
operating plungers, or by a threaded adjustment of the tappet rod, or 


-'V -y ? 















193 



Construction and Design of Engine Parts 

the use of a small screw at the end of the rocker arm to contact with 
the valve stem. The proper position of a rocker arm on a valve-in- 
the-head motor, when the valve is closed, is shown at Fig. 103, A. 
There should be 0.010 inch clearance between the valve stem and 
the end of the rocker arm when the valve is fully closed, in order to 
provide for lengthening of the valve stems due to expansion from heat. 
The position of the rocker arm with the valve half open is shown at B, 


Fig. 102.—Sectional View Showing Point in Crank Pin Travel at’ 
Which Exhaust Valve is Fully Closed and When Inlet Valve Be¬ 
gins to Open. 

and the angle assumed by the valve lever when the valve is fully 
opened is shown at C. If the fulcrum is exactly at the center of the 
rocker arm, the opening or lift of the valve may be readily ascertained 
by measuring the travel of the tappet rod center line which is indicat¬ 
ed in the illustration by the distance between the diverging center lines. 






104 


Motorcycles , Side Cars and Cyclecars 


Pistons and Rings. —Pistons are invariably made of cast iron 
in motorcycle power plants, though steel has been employed to a 
limited extent in aeroplane and very high-speed automobile and cycle 
motors. The piston is always less in diameter than the bore of the 
cylinder, in order to provide space for an oil film between the piston 
and cylinder walls. In order to prevent leakage of the gas, elastic or 
spring packing members called piston rings are inserted in grooves 
in the piston. It is common practice to provide three rings which 
are usually placed above the wrist-pin. In some constructions, two 
rings are placed at the top and one at the bottom of the piston, and 



Fig. 103.—Positions of Rocker Lever Used in Depressing Overhead 
Valves. A—Showing Clearance When Valve is Closed. B—Valve 
Half Opened. C—Rocker Arm Position With Valve Fully 
Opened. 

it is contended that this makes for steadier support of the piston as 
well as preventing, as much as possible, the leakage of compression. 

The most popular form of piston is the flat-top type depicted in 
the assembly of engine parts at Fig. 104 and very clearly outlined in 
the various sectional views of complete power plants previously pre¬ 
sented. In some engines, domed-head pistons are employed, while 
those used in two-cycle motors have a projecting ridge or raised.por¬ 
tion to deflect the fresh gas coming in from the transfer passage to 
the top of the cylinder. The piston rings are of two general forms, 
one termed “eccentric” because the ring is thicker at one portion, and 
the “concentric” in which the ring is of uniform thickness and the 
























































































('on struct ion and Design of Engine Parts 195 

circles representing the inner and outer peripheries of the ring are 
concentric to each other. In order to permit of installation of the 
piston rings on the piston, they are split at one point, and have suf¬ 
ficient elasticity so that they may be snapped in place in the grooves 
made to receive them on the piston wall. Two forms of joints are used 
in piston rings; one is the diagonal cut, the other is termed the 
“stepped” joint. Some makers provide a small pin in the ring groove 



Fig. 104.—Group Showing Some of the Internal Parts of the Reading- 
Standard Twin Cylinder Motor. Note Arrangement of Connect¬ 
ing Rod Assembly. 


to keep them from working around, because if the slot in the three 
rings should happen to get in line, there is apt to be a loss of com¬ 
pression with the diagonally split rings. With the stepped joint, it 
is not so important to use the stop pins as the character of the joint 
is such that leakage is reduced appreciably, and it is considered good 
practice to have the rings free to move, because it makes for more 





196 Motorcycles , Side Cars and Cycle-cars 

even wear on the cylinder wall." The piston rings fit their grooves 
snugly but yet are free to move circumferentially though not up and 
down in the groove. 

The argument advanced in favor of the dome piston top is that 
the arched construction is stronger, and that the liability of accumula¬ 
tions of oil being deposited on the arched head is less than with a flat 
head which in some cases may actually- have a slight depression at 
its center. The flat top form is easier to machine. 

Wrist Pin and Connecting Rod Arrangements.—The upper 



Fig. 105.—Components of Twin Cylinder Connecting Rod Assembly 
Taken Down to Show Design of Connecting Rod Big End. 


end of the connecting rod oscillates on a short steel shaft that passes 
through suitable bosses in the piston. Wrist pins are usually of 
hardened steel and may be of solid cylindrical or tubular section. The 
tubular section is preferred because oil may accumulate in the interior 
of the hollow wrist pin which acts as a reservoir for its retention, and 
from which it may be directed to the wrist-pin bushing, usually of 
phosphor bronze. The retention of the wrist pin is by positive means, 
because if this member is permitted to move sideways in the piston 
it is apt to wear a wide groove in the cylinder wall, as the hard and 









Construction arid Design of Engine Parts 


197 


sharp edges of the wrist pin act the same as a planer tool when the 
piston reciprocates in the cylinder. These grooves generally ruin the 
cylinder, because they are so deep that there would not be enough 
metal left for strength if the cylinders were rebored. The commonest 
method of wrist pin retention is to use a set screw which passes 
through the boss of the piston and into the wrist pin. If that member 
is hollow, a small split pin may be passed through the end of the set 
screw projecting into the wrist pin interior to prevent it from backing 
out. In some cases, the set screw is kept from backing out by a 
lock nut. 

The wrist pin does not always have a bearing in the upper end of 
the connecting rod, as sometimes the connecting rod is clamped to 
the wrist pin member so this member must oscillate in suitable bush¬ 
ings pressed into the piston bosses. This method of construction has 
an important advantage, inasmuch as considerably more bearing sur¬ 
face is obtained than when a bushing is forced into the upper end of 
the connecting rod, which must be comparatively narrow in order to 
fit between the bosses on the piston. Another advantage is that the 
wrist pin is positively clamped and is thus prevented from end move¬ 
ment. The various common methods of wrist pin retention may be 
clearly understood by referring to the many sectional views of typical 
motorcycle power plants presented in this and the preceding chapter. 

Connecting rods are invariably steel drop forgings and are made in 
two main types. The simplest of these is the one-piece rod which is 
used on engines having built-up crankshafts, while the other is neces¬ 
sary on multiple-cylinder engines using one-piece crankshafts, and is a 
two-piece form because the lower end is divided so a portion forms a 
cap for the bearing. Half of the main bearing is attached to the con¬ 
necting rod, while the other half of the bushing is firmly secured to 
the connecting rod cap. The cap and connecting rod are joined 
together by substantial bolts. 

The connecting rod of a single-cylinder engine is very simple, and 
is of the general form indicated at Fig. 105, A. In the majority of 
twin-cylinder engines, one of the connecting rods is forked at the lower 
end, as shown at B, Fig. 105, and the rod that works in connection 
with it has a single end which fits between the fork members of the 
other. Both rods work on a common crank pin. Connecting rod A, 


198 


Motorcycles , Side Cars and Cyclecars 



at Fig. 105, is provided with a bushing having a sufficiently large bore 
so that it will work freely on the outside of a large bushing that is 
forced tightly in place in the fork sides of connecting rod B. The 

bushing that fits the 
forked rod is adapted to 
bear directly on the 
crank pin. It will be ap¬ 
parent that the bushing 
in connecting rod A is 
employed on an oscillat¬ 
ing bearing, whereas that 
in connecting rod B re¬ 
volves with the crank pin, 
and is therefore subject 
to wear on its inside by 
the friction of the crank 
pin and on its exterior by 
the bushing of connecting 
rod A. 

Another method of 
double connecting rod 
arrangement is shown at 
Fig. 106. In this, the 
main connecting rod en¬ 
circles the crank pin and 
carries a lug above the 
crank pin to which a 
shorter rod is attached. 
The long member is usu¬ 
ally called the “master” 

Fig. 106.—Connecting Rod and Crankshaft connecting rod. 

Assembly of the De Luxe Twin Cylinder The connecting rod 

Motor. , r . 

arrangement of the 

Premier (English) engine differs considerably from conventional 

practice because the arrangement of the rods is such that both 

pistons move together in their respective cylinders, and reach 

the ends of the up and down stroke simultaneously. With 




Construction and Design of Engine Parts 199 


the connecting rod arrangement commonly employed on twin- 
cylinder V-motors, one of the pistons reaches the end of its 
stroke in advance of the other, and it is impossible to obtain an 
even sequence of explosions, i. e., to have them separated by equal 
intervals. With reference to the Premier connecting rods assembly, 
which is depicted at Fig. 107 in connection with the fly-wheel assembly 
and at Fig. 108 in the engine interior, rod A conforms to conventional 

practice and its lower end en¬ 
circles the usual form of crank 
pin joining the fly-wheels to form 
a crankshaft assembly. Rod B, 
however, is a forked member that 
fits bosses cast on the fly-wheel. 
The arrangement of these bosses 
is such that as the fly-wheel as¬ 
sembly revolves the pistons will 
move exactly the same distance, 
and it is, therefore, possible to 
have the explosions just as evenly 
spaced as when a double cylinder 
opposed engine is used or a twin- 
cylinder tandem arrangement 
with both connecting rods at¬ 
tached to a common crank pin. 

Crankshaft Forms and Fly¬ 
wheels. —The common construc¬ 
tion of the crankshafts of one 
and two cylinder motorcycle 
power plants is a built-up type 
in which the fly-wheels form an 
important part of the assembly. 
In the four-cylinder forms, the crankshaft is a four-throw, one- 
piece pattern just as in automobile practice. A typical built- 
up crankshaft and fly-wheel assembly is outlined at Fig. 109. 
In this, the crank-pins are pressed into suitable bosses at the center 
of the fly-wheel webs. The crank-pin is a tight fit, and is forced in 
place with an arbor press. To prevent loosening, a key is added as a 



Fig. 107.—Unconventional Connect¬ 
ing Rod Arrangement Utilized 
in Premier Two Cylinder 
Motor. 





200 Motorcycles , Side (Jars and Cyclecars 

further precaution, and the end of the pin is riveted over. The crank 
pin is provided with a threaded portion at each end, and clamping 
nuts are used to draw the two fly-wheels tightly in place against a 
shoulder on the crank pin. The assembly is therefore composed of 
two fly-wheel castings, which in this case are duplicate members, 



except that one is a right and the other is a left; the crank-pin and the 
two portions of the main shaft that are riveted in the fly-wheel hubs. 
In taking this assembly apart, the fly-wheel and main shaft relation 
is not disturbed because the two fly-wheels may be easily separated 












Construction and Design of Engine Parts 201 

to release the crank-pin and connecting rod by loosening and remov¬ 
ing the clamping nuts on the crank pin. Other forms of built-up 
crankshafts similar in general design to this one are shown in sectional 
views of power plants in various portions of this treatise. 

The crankshaft outlined at Fig. 110 is the one used on the new 
Triumph (English) two-cylinder vertical tandem motor. The crank¬ 
shaft is a one-piece pattern similar to that employed in automobile 
practice, and the connecting rods are of the two-piece form with a 
removable lower cap portion to permit their assembly on the one- 
piece shaft. The crankshaft shown at Fig. 111 is that used on the Iver- 
Johnson twin motor, and employs a double crank-pin which is ar¬ 
ranged so the cylinders fire at equal intervals the same as in the double 
cylinder opposed type. The construction is such that the fly-wheel 
castings are securely attached to the drop-forged crank which has the 
crank pins in staggered relation. With this arrangement, the cylinders 
are not exactly in the same plane, i. e., their center lines do not coin¬ 
cide with the center line of the crank-case as is common practice. 
One cylinder is set to the right and the other to the left of the engine 
center, in order to allow for the double crank-pin arrangement. 

The crankshaft arrangement of a typical four-cylinder engine with 
one of the connecting rods and its piston in place is shown at Fig. 
112. This crankshaft has four crank-pins joined together by a series 
of web members and three main journals. The entire assembly is 
forged in one piece, and follows automobile practice in all respects 
except that of size. Two of the crank-pins are on the same plane so 
that two of the pistons travel up and down together. The usual ar¬ 
rangement is to have the two center pistons move in conjunction and 
the two end ones to go up while the center ones are going down and 
vice versa. 

The method of fly-wheel attachment on the four-cylinder crank¬ 
shaft depicted is clearly outlined at Fig. 92. The fly-wheel hub is 
tapered to fit the taper on the crankshaft, and is also keyed in place 
to prevent the fly-wheel from turning. A substantial clamp nut on 
the threaded end of the crankshaft serves to keep the fly-wheel pressed 
firmly on the taper. The endeavor of the designers is to make the 
fly-wheels as large as the design of the engine permits and to have 
the rims reasonably heavy because the farther away the weight is 


Motorcycles , Side Cars and Cyclecars 


202 


^ ^Xyl i nder 





Crankshaft 
CDr\v« Side) 


FlywVeeV 


SpV ?a\ Tixnmd 
' Gears 


tAau» shaft 
CTiminj Side) 

gine Base 


Fig. 109.—Sectional View of Crank Case of AMC Motor, Showing 
One Method of Assembling Built Up Crank Shaft in Which the 
Flywheel Webs are Utilized for Supporting the Crankpin, 


carried from the crankshaft center the more effective does the fly¬ 
wheel become as an evener of engine movement. As has been pre¬ 
viously explained, the momentum acquired by the fly-wheel during 
the expansion or power stroke of the engine is depended on to keep 
the pistons, valves, etc., in operation during the strokes in which no 


















































































Construction and Design of Engine Parts 


203 


power effort is being applied to the crankshaft, and under conditions 
where a decided resistance may be offered to piston movement, as 
during the compression stroke. Heavy fly-wheels permit an engine 
to run steadily at low speed and also reduce vibration. The size and 
weight of the fly-wheel rim depends upon the size of the cylinder and 
the amount of compression. While most fly-wheels used in motorcycle 
engines are of cast iron, some makers employ steel forgings even in 
the built-up form of crankshaft. The fly-wheel of a single-cylinder or 
a two-cylinder V-engine usually has incorporated with it the counter¬ 
weights provided to balance that 
of the reciprocating parts and to 
promote smooth running. 

Engine Base Design and 
Construction. — The conven¬ 
tional method of constructing 
the crank-case of a one or a two 
cylinder motorcycle power plant 
is to form that member in two 
piece, 3 , which join together on 
the engine center lines. The two 
halves are made of aluminum 
alloy, and the joints are of the 
matched form, in order to make 
the crank-case oil-tight. The tim- 
Fig. 110.—Crankshaft Arrangement ing gear chamber is usually cast 

tical Engine^ W ° ^ ylinder Ver ~ integral with one of the halves 

of the crank-case. The two por¬ 
tions are clamped tightly together by through bolts, extending from 
one side to the other. The timing gear case is sometimes known as 
the distribution chamber, and is either provided with a cover or is 
in itself removable, in order to gain access to the timing gears and 
valve-operating mechanism. The aluminum crank-case is preferred, 
though on some cheap engines cast iron has been employed. The 
only objection against the cast iron is that it weighs nearly three 
times as much as the lighter alloy commonly used. The cast iron is 
equally strong and will hold threads better than the softer metal. 
This method of crank-case construction is shown at Fig. 74. 

















£04 


Motorcycles , Side Cars and Cyclecars 




Another form in which the crank-case member itself is the full 
width of the engine and not divided vertically in the center is shown 
at Fig. 77. In this, a removable side plate enables one to gain access 
to the engine interior and is securely held in place against the crank¬ 
case proper by a series of studs. 

When multiple-cylinder engines are used, as at Fig. 92, automobile 
practice is followed in that the crank-case is made in two portions 
and is split horizontally. The upper portion serves as a base for 
attaching the cylinders and also carries the main bearings, and. the 

lower portion is utilized as an 
oil pan and is not subjected to 
any strain. The engine is sup¬ 
ported in the frame by lugs cast 
with the upper half of the crank¬ 
case. 

The crank-cases of most en¬ 
gines are provided with some 
form of gauge glass, in order 
that the rider may be able to 
ascertain the amount of oil pre¬ 
sent in that member. In single 
and double cylinder engines, a 
non-return ball check valve is of¬ 
ten screwed into the crank-case 
to permit the air compressed 
therein, each time the piston 
moves down, to escape, and usu¬ 
ally a small piece of copper tube directs the escaping air to a 
point underneath the crank-case to insure that the oil with 
which the air is saturated will not soil the machine. The bearings 
used in the crank-case may be of two forms, the plain bushing, 
made of phosphor bronze or other suitable bearing metal, or anti¬ 
friction bearings of the ball or roller type. The four-cylinder power 
plant depicted at Fig. 92 uses plain bushed bearings while that at 
Fig. 74 has anti-friction bearings of the ball type to support the 
crankshaft assembly. The engine at Fig. 79 is a plain bearing form 
throughout as the main bearings, as well as those at the upper and 



Fig. 111.—Crankshaft Arrangement 
of Iver-Johnson Twin Motor. 



























Construction and Design of Engine Parts 205 

lower end of the connecting rod, are in the form of bronze bushings 
forced in place in the crank-case bosses. 

Plain and Anti=Frictional Engine Bearings. —Decided ad¬ 
vantages are obtained when ball or roller bearings are used to support 
the crankshaft, because these not only simplify the lubrication prob¬ 
lem but they also reduce friction to a minimum, which makes the 
engine freer running. It is claimed that engines fitted with anti¬ 
friction bearings are more “lively,” and are faster than the plain 
bearings forms. Anti-friction bearings are well adapted to this work, 
and the successful application of ball and roller bearings in racing 



Fig. 112.—Four Cylinder Crankshaft of the Three Main Bearing Type. 


motors has demonstrated forcibly the advantages of substituting roll¬ 
ing for sliding friction at all points where copious lubrication is ques¬ 
tionable. To use bearings with rolling members successfully, it is 
necessary to not only make proper size selections but to install them 
correctly as well as make provision for adequate lubrication, though 
bearings of this form will run with considerably less oil than plain 
bushings. As much less heat is evolved through the reduction of in¬ 
ternal work due to friction, anti-friction members will prove more 
enduring and be capable of more extended periods of operation with 
materially less lubricant, which is depended on in a plain bearing for 






206 


Motorcycles, Side Cars and ('y decors 


separating the metal surfaces and at the same time to conduct away 
the heat evolved at high speeds due to rubbing of surfaces over each 
other. 

In order to prove that space limitations, to which motorcycle de¬ 
signers adhere so closely, make it difficult to use properly designed 
journals of the plain bearing type, the reader is asked to study the 
following brief analysis of the loads present upon a typical connecting- 
rod assembly using plain bearings and depicted at Fig. 113, and the 
bearing area provided to resist them. In this, rod A is the member 
attached to the main bushing encircling the crank-pin, while rod B is 
a forked member with the big ends bearing upon the outer surface 
of the main bronze bushing. The bore of the main bushing is 13 4 
inches, its length is 1J4 inches. The outside diameter is 1% inches, 
and the width of the forked connecting rod members is 7 /16 inch 
each side. The projected area of the bushing serving rod A can be 
represented by a rectangle 13 4 inches by lj^ inches, which has an 
area of 1.875 square inches. The projected area of the bearing surfaces 
serving rod B can be represented by a rectangle % inch by \% 
inches and has an area of 1.53 square inches. 

Before considering the application of anti-friction bearings, let us 
first briefly review some of the conditions governing plain bearing 
construction, and then we can understand how the motorcycle de¬ 
signer is forced to make his bearing design, especially as relates to 
connecting-rod big ends, a compromise that will endeavor to reconcile 
widely differing factors. Some of the essentials considered in plain 
bearing designs, are: Proportions and dimensions of bushing as re¬ 
lates to diameter and length; selection of suitable bearing metal; the 
amount of clearance to be allowed between shaft and bearing, and 
provisions for lubricating. Considering first the proportions, these 
depend upon various conditions, such as: Size of the shaft, which 
must be strong and stiff and which must be of sufficient diameter to 
obtain this strength, and enough length so the bearing pressures will 
not exceed a certain value in order to retain an oil film. Contrasted 
to these are the opposing conditions that circumferential or rubbing 
speed must be low to reduce the work of friction (which calls for small 
diameters) and also that the bushing length be held to a point where 
there can be no concentration of pressure from deflection (which calls 


Construction and Design of Engine Parts 207 

for short bearings) on any limited area of the bushing surface. 

As to proportions, most engineering authorities recommend that 
engine bearings be at least 1.5 times as long as the diameter of the 
shaft where space considerations permit. In the main bearing of the 
connecting-rod assembly described, the ratio is considerably less than 
this as the length is but 20 per cent, greater than the diameter, and 
in the bearings of rod B, the length is but half the diameter. Here 
we have the first departure from good engineering practice. 



are to carry and the bronze used has a high degree of resistance to 
deformation, and on the main bearing at least it is working in com¬ 
bination with a hardened steel crank-pin. Conditions are not so 


favorable at the forked oscillating bearing, however, as here the rod 
ends are comparatively soft where they bear against the outside sur¬ 
face of the bronze bushing. The value for safe working stress on 
crank-pin bearings is given as 1,280 pounds per square inch projected 




























*208 


Motorcycles , Side Cars and Cyclecars 


area for hard steel and bronze in combination, and as 800 pounds per 
square inch for unhardened steel on bronze. 

The main crank bushing of the connecting rod assembly at Fig. 113 
bears against a hardened steel pin so the higher value applies, but the 
oscillating member, which is soft enough so it can be cut with a file 
bears against bronze, so the lower value must be used. The pistons 
used are V/i inches bore, which means that the piston top area is 
9.62 square inches. If we assume an explosion pressure of 300 pounds 
per square inch, which value may obtain at times in all power plants, 
this gives us a value of 2,886 pounds as the force of the explosion on 
the piston top. At a speed of 2,000 revolutions per minute, it should 
be considered that the main crank-pin bushing, which takes the ex¬ 
plosion pressure of each cylinder is subjected to this force 2,000 times 
per minute as an explosion is obtained for each revolution, and both 
pistons must impart their pressure directly against the one crank- 
pin. We have seen that the projected area of the main crank-pin 
bushing is 1.87 square inches, so we can find the unit stress per square 
inch bearing surface by dividing the total pressure by the available 
projected area. This gives us a value of 1,543 pounds per square 
inch and shows that the main bearing would be overloaded nearly 
300 pounds per square inch if only the explosion pressure was con¬ 
sidered. 

There are other loads on the bearing that must be added, one of 
these being the load due to centrifugal force of the rapidly rotating 
connecting-rod big ends as well as the inertia loads produced by the 
reciprocating members. To discuss these would be to complicate the 
discussion so that it would be difficult of comprehension by the 
average reader and it would serve no useful purpose because the load 
due to explosion pressure alone brings an overload on the bearings. 
Considering the load on the forked big end, we find that the projected 
area of 1.53 square inches is subjected to a load of 2,886 pounds at 
instant of explosion. This means a unit stress of 1,886 pounds per 
square inch on a bearing suited only for 800 pounds per square inch, 
and means an overload of 1,086 pounds or over 125 per cent. 

This insufficient bearing area is obviously the reason for some of 
the trouble experienced with plain journals, as it is apparent that 
high unit pressures will squeeze the lubricant from between the sur- 


209 


Construction and Design of Engine Paris 

faces and produce an actual metallic contact at times between bushing 
and crank-pin. The overload on the bearing is not serious enough to 
deform either bearing metal, but it certainly does promote cutting 
and scoring the bushing and crank-pin through the failure of lubrica¬ 
tion. The lubricant forced from between the surfaces is thrown off 
of the rapidly revolving crank-pin by centrifugal force, and, unless 
new oil is supplied in a positive manner, the surfaces will be in actual 
metallic contact from time to time. Under the conditions outlined, 
it is not strange that plain bushings subjected to such severe service 
should depreciate rapidly. 

The problem of main bearing design is not a serious one, as these 
can always be made sufficiently large, and there is no force tending 
to throw the oil out to any injurious degree when the fly-wheel 
assembly they support revolves. Another important point is that two 
bearings can be used to support the load that one crank-pin bushing 
of less than half their projected area must take. This condition alone 
is much more favorable to endurance, because the film of lubricant 
remains between crankshafts and bushings, and unit pressures are not 
high enough to squeeze it out. 

Two forms of anti-friction bearings are used in connecting-rod big 
ends, and for crankshaft support. The roller bearing has advantages 
of moment in this application, but it has more friction than a properly 
applied ball bearing. The crank-pin, which is hardened and ground, 
forms an ideal surface for the bearing rollers to work on, and as the big 
end of the connecting rod can be hardened and ground very accu¬ 
rately a free running bearing can be obtained that will not be materi¬ 
ally larger in diameter than a plain form, except for the difference 
in thickness between the bronze bushing and the roller members. The 
error commonly made is to make the rollers too small in diameter, 
and, while it is very desirable to keep the dimensions of the big end 
bearings down as much as possible, it is a harmful tendency when 
earned to extremes. Rollers are ordinarily about % inch in diameter, 
whereas, if proportioned in accord with the loads upon them, they 
should be H inch in diameter, at least. 

If comparison is made between ball bearings and the rollers or¬ 
dinarily used, it will be vyell to state that a roller bearing of sufficient 
capacity would be nearly as large, though some space would be saved 


210 


Motorcycles , Side Cars and Cyclecars 


by the elimination of the outer race member needed with the ball 
bearing. The rollers bear directly against the metal of the connecting 
rod but the balls run in a separate hardened race member which has 
a groove of proper curvature for the balls to run in, and which is 
retained by the connecting rod big end. Either form indicated will 
give good service, though where the design permits, the most efficient 
bearing, which is the ball type, will prove more enduring. 

The writer knows that considerable trouble obtained with the early 
ball bearings used for this purpose but in practically all cases, it could 
be ascribed to the desire to use bearings of small size, fostered to 
some extent by the wishes of designers more familiar with bicycle 
practice than with the requirements of self-propelled vehicles, and 
also to the competition between the manufacturers of such bearings. 
If one manufacturer recommended a larger bearing than a competitor, 
the business went to the maker selling at the lowest price, regardless 
of the merits of the bearing or its capacity for the work. The ultimate 
consumer was not the only one who suffered by this policy as the 
failure of such bearings reacted against the motorcycle builder, who 
promptly shifted the blame to the bearing manufacturer, who had to 
take it whether it belonged to him or not. This created the erroneous 
impression in some quarters that ball bearings were not as well suited 
to the work as roller bearings, whereas when properly selected and 
installed, these bearings answer all requirements besides running with 
minimum friction. 

While a roller bearing is somewhat less in diameter than a ball 
bearing of the same capacity, it is wider and will contain nearly the 
same amount of metal. If the connecting rod big end wears it in¬ 
creases in bore, and either larger rollers or a new rod are needed. 
With a ball bearing, the outer race is an integral part of the bearing, 
it can be ground and fitted to the balls very accurately, as well as 
made of proper material. Ball bearing race members are usually of 
chrome steel, which has superior resistance while the drop forged rods 
are usually of a low carbon steel and must be carbonized at the bearing 
point, and treated before a sufficient degree of hardness can be ob¬ 
tained. With a ball bearing, the outer race is not only of proper stock 
treated independently, but the rod does not need other than a 
toughening treatment, if any, which does not call for carburizing. 


Construction and Design of Engine Parts 211 

While the writer does not mean to imply that roller bearings are 
wanting in reliability, or other features, out of justice to the ball 
bearing it is necessary to outline their advantages over the other 
types. 

One of the conditions that has materially interfered with efficient 
ball bearing service has been the methods employed in installing them. 
A sectional view of the engine base of a power plant of European 
design is shown at Fig. 114, and this depicts the method of mounting 


FLOATING OUTER 
BEARING RACE 


ALUMINUM 
TIMING GEAR CASE 


MAIN SHAFT 


BEARING INNER 
MEMBER FORCED 
ON SHAFT 


✓PLAIN BRONZE 
BUSHING 


iLUMINUM 
HOUSING 

✓VARIABLE PULLEV 



'FLV WHEEL 


Fig. 114.—Sectional View of Crank Case, Showing Application of Sin¬ 
gle Row Ball Bearings in Supporting Flywheel Assembly. 


usually employed. If the work of fitting is carefully done, the mount¬ 
ing will give satisfaction, though in the rush incidental to regular 
manufacturing, bearing inner race members are apt to be pushed on 
shafts machined a trifle small rather than forced on. The outer races 
rest directly in the housing of soft material, usually cast aluminum. 
While the bearing does not loosen up at once, still the constant suc¬ 
cession of shocks due to explosion pressure tends to pein out the 
stressed metal supporting the outer race member. This enlargement 

























































































































212 Motorcycles, Side Cars and Cyclecars 

of the bearing housing permits the outer race to turn, and soon it is 
a very poor fit in the crank-case. The same applies to the inner race, 
which becomes-loose on the shaft, so loose in fact, that the shaft will 
become scored and appreciably reduced in diameter. This condition 
is not exaggerated one iota, the crank-case of several ball bearing 
machines under the writer’s observation have worn in just the manner 
indicated, and the bearing supporting shafts also. 

Of course, bearings of standard bore and diameter cannot be used 
for replacement purposes, and the only remedy is to bush the housings 
with a steel or bronze member after it has been bored out enough to 
accommodate it, providing there is metal enough in the bearing hous¬ 
ing walls. If the shaft is scored, it can be turned down enough to 
permit a steel bushing being forced on, this being machined so the 
outside diameter corresponds to the bearing bore. An alternate 
method, the more costly and satisfactory one, is to replace the de¬ 
fective members with new parts. 

Installing the ball bearings in this manner is not the best practice, 
and no less an authority than Riebe, in a recent address before an 
engineering society, condemned the common practice as shown at 
Fig. 114, and advised the positive retention of bearing inner races by 
clamping members, as well as the housing of the outer races 
in bushings of . harder material than the aluminum commonly 
used for crank and gear cases. As this engineer is one of the pio¬ 
neers in the design of ball bearings, such advice cannot be passed by 
lightly. 

The writer desires to submit a suggestion for the design of a twin- 
cylinder crank-case at Fig. 115, in which the bearing installation is on 
correct engineering lines as advised by leading authorities. To begin 
with, the design is different from that usually followed in that the 
cylinder centers are placed one to each side of the crank-case center 
line or in staggered relation. This point, no doubt is open to criticism, 
inasmuch as it makes for a slightly wider crank-case and more ex¬ 
pensive construction. At the other hand, it would appear that if the 
front cylinder is set a little to one side, that the rear cylinder will 
receive some effect from the air draft created by cycle movement, and 
that more complete cooling will result. This placing of the cylinders 
independently of the crank-case center line makes it possible to use 


Construction and Design of Engine Parts 


213 



Fig. 115.—Design Drawing Showing Correct Application of Ball 
Bearings to Connecting Rod Big Ends as Well as Main Bearings 
of Twin Cylinder Motorcycle Power Plants. Note Automatic 
Lubrication System Provided. 

ball bearings of correct proportions on the crank-pin, as each con¬ 
necting rod has its independent anti-friction bearing. 

The ball bearings are special in that they are assembled on the 
crank-pin, which takes the place of the bearing inner race members, 


















































































































214 


Motorcycles , Cars and Cyclecars 


but as the balls, separators, outer races and even curvature of the 
inner ball races on the crank-pin Conform to standard practice, such 
a bearing should not cost appreciably more than the regular standard 
product and a remarkable saving is effected in bearing diameter by 
forming the ball races on the crank-pin in the manner indicated. The 
outer races are kept from side movement by a clamping bolt passing 
through a slotted boss just above the bearing. As the outer race 
members may be ground within .0002 inch plus or minus, it will be 
apparent that but little bolt movement will suffice to hold the outer 
race firmly in place in connecting rod big ends. 

Special attention is directed to the main bearings and the method of 
retention. Both are housed in supplementary pressed steel container, 
forced into the soft aluminum crank-case, these members of hard 
material resisting deformation due to alternate shock stresses much 
better than the softer alloy they protect. The bearing on the drive 
side has a clamped inner race, held tightly against a shoulder on the 
fly-wheel bjr a threaded clamping nut and the outer race, while not 
tightly clamped by the housing cap, is held so it will not have any 
more than .01 inch end movement. The inner race of the bearing at 
the timing gear end is clamped between shoulders on the fly-wheel 
shaft and timing gear, which member is firmly pressed against the 
inner race by the threaded retention nut. The outer race is allowed 
to float in its pressed steel container. 


CHAPTER IV. 


LUBRICATION, CARBURETION AND IGNITION. 


Theory of Lubrication—Forms of Lubricants—Devices for Supplying Oil— 
Sight Drip Feeds—Simple Splash System with Hand-Pump—Mechanical 
Oilers—Lubricating Two-Cycle Engines—Motorcycle Fuel, Its Deriva¬ 
tion and Use—How Fuel is Carried—Principles of Carburetion Out¬ 
lined—What the Carburetor is for—Early Vaporizer Forms and Their 
Defects—Elements of Carburetor Design—Features of Automatic Car¬ 
buretors—Typical Motorcycle Carburetors—Foreign Carburetor De¬ 
signs—Methods of Carburetor Adjustment—Typical Mufflers and How 
They Operate—Use and Abuse of the Muffler Cut-out Valve—How 
Compressed Gas is Ignited—Parts of Simple Battery System—High 
Tension Magneto Action—Operation of Standard High Tension Magneto 
—Magneto Driving Means—Ignition Timing—Detection of Faults. 

Theory of Lubrication.—All bearing surfaces, no matter how 
smooth they appear to be to the naked eye, have minute projections, 
and, when examined under a microscope, the surface of even a finely 
finished bearing appears rough. If bearings were run without oil, the 
microscopic projections on the shaft and on the bushing or box in 
which the shaft revolves would tend to interlock, and a great amount 
of friction would result. This would mean that much of the power 
developed by the engine would be utilized in overcoming this resist¬ 
ance. Without some means of minimizing this loss, considerable heat 
would be generated if the bearings were run dry, and, as a result, the 
overheated bearings would soon depreciate and would give signs of 
distress long before they failed by becoming firmly burned together. 

The reason a lubricant is supplied to bearing points will be readily 
understood if one considers that the close-fitting surfaces of the shaft 
and bushings are separated by this elastic substance, which not only 
fills up the minute depressions, thus acting as a cushion, but which 
absorbs the heat generated by friction as well. In properly lubricated 
bearings, the oil takes all the wear that would otherwise come on the 

215 



216 Motorcycles , Side Cars and Cyclecars 

metallic bearings. The grade of oil and amount to use depends en¬ 
tirely on the bearing points where it is to be applied. An oil that 
would be entirely suitable for lubricating the interior surfaces of the 
gas-engine cylinder would not be suitable for bearings in some cases 
if these were subjected to heavy pressures. At the other hand, the 
semi-fluid oil or grease which cushions the teeth of the driving and 

change speed gearing 
so well could not be 
used in the cylinders 
of the engine. 

When used for air¬ 
cooled engine lubri¬ 
cation, an oil must be 
capable of withstand¬ 
ing considerable heat, 
in order that it will 
not be evaporated or 
decomposed by the 
hot metal of the cylin¬ 
der. The oil used for 
cylinders or bearings 
should have a low 
cold test, i. e., it should 
not thicken up at low 
temperatures so that 
it will not flow freely. 
All authorities contend 
that lubricants must 
be free from acid which will corrode the metal surfaces to which the 
oil is applied. A lubricant must have sufficient body to prevent 
metallic contact of the parts between which it is depended upon 
to maintain a resilient film. It should not have too high a body 
or too much viscosity because a lubricant that is too thick will 
have considerable friction in itself, and will not flow readily between 
bearing surfaces. 

If the lubricant is to be used in gearing where great cushioning 
qualities are desired in addition to positive lubrication, it must have 


NLET 


STUFFING 

BOX 


Ih 

H^i 


w. 

— J 


JIIP 


lH 

jf\ 


/ yy 

v jh. 

. 

Is, SPUD 

'//7vv\ 



OIL FEED 
REGULATING 
NEEDLE VALVE 


CORK PACKING 


SIGHT FEED 
GAUGE GLASS 


OUTLET 


Fig. 116.—Diagram Showing Construction of 
Drip Feed Lubricator. 




































Lubrication , Varburetion and Ignition 


217 


a heavy body and the semi-solid graphite greases are the best materials 
to use for this purpose. The grease or oil should also be free from 
injurious adulterants of either vegetable or animal origin, because 
these invariably contain fatty acids that will decompose and attack 
metal surfaces or gums which will coagulate or oxidize by exposure 
to air and retard the action of the bearings. The best lubricants for 
motorcycle use are derived from a crude petrolemn base with the 
exception of graphite which is a form of pure carbon that is a good 
lubricating medium for certain purposes. 

Forms of Lubricants. —Oils of organic origin, such as those ob¬ 
tained from animal fats or vegetable substances, will absorb oxygen 
from the atmosphere which may cause them to become rancid. As 
a rule, these oils have a very poor cold test, because they solidify at 
comparatively high temperatures. Their flashing point and fire test 
are also so low that they are not suitable at points where considerable 
heat exists, such as the interior of a gas engine. The only oil that is 
used to any extent in lubricating gas engines that is not derived from 
a petroleum base is castor oil, which is obtained by pressing the seeds 
of the castor plant. This has been used on high-speed racing motor¬ 
cycle engines and on aeroplane power plants, where it is practically 
pushed right up past the piston and out of the combustion chamber 
with the exhaust gases, so fresh oil must be supplied all the time to 
replace that ejected from the engine. Obviously this method of oiling 
would not be considered economical, and would not be suitable on 
either business or pleasure automobiles or motorcycles. 

Among the solid substances that have been used for lubrication to 
some extent may be mentioned tallow, which is obtained from the 
fat of certain animals, such as cattle and sheep, and graphite, which 
is a natural mineral product. Tallow is usually employed as a filler 
for some of the greases used in transmission gearing, but should never 
be utilized at points where it will be exposed to much heat, and even 
under these conditions pure mineral greases are to be preferred. 
Graphite is obtained commercially in two forms, the best known being 
flake graphite, where it exists in the form of small scales or minute 
sheets, and the deflocculated form, where the graphite has been ground 
or otherwise divided into a dust. It is usually mixed with oil of high 
viscosity and used in connection with lubrication of change speed 



218 


Motorcycles , Side Cars and Cyclecars 


or power transmission gear parts, though it has been mixed with 
cylinder oil and applied to engine lubrication with some degree of 
success. Graphite is not affected by heat or cold, acids or alkali, and 
has a strong attraction for metal surfaces. It remains in place better 
than an oil, and, as it mixes readily with oils and greases, their effi¬ 
ciency for many applications is increased by its use. 

Any oil that is to be used in the gasoline engines must be of high 
quality and for that reason the best grades are distilled in a vacuum 
so the light distillates will be separated at a much lower temperature 
than ordinary distilling practice permits. When distilled at the lower 
heat, the petroleum is not so apt to decompose and deposit free 
carbon. A suitable lubricant for gas-engine cylinders has a vaporizing- 
point at about 200 deg. Fahr., a flash point of 430 deg. Fahr., and a 
fire test of about 600 deg. Fahr. Cylinder oil is one lubricant that 
must be purchased very carefully. A point to remember is that the 
best quality oils, which are the most efficient, can only be obtained 
by paying well for them. The few cents saved in using a cheap oil 
is not of much moment when compared to the repair bill that may 
accrue from its use. The cheap oil will not only deposit carbon very 
freely in the cylinder heads but is liable to gum up the piston rings 
and valves, and detract much from the smooth operation and power 
capacity of the motor. 

Devices for Supplying Oil. —When the internal combustion en¬ 
gine was first evolved, the importance of adequate lubrication to 
secure efficient engine action was not as fully realized as it is at the 
present time. Practically all of the early forms of engines were slow 
acting and the problem of lubrication was not as serious as that which 
confronts the present-day designer of high-speed power plants. The 
earliest system of oil supply was by filling the crank-case to a certain 
level, and depending on the rotating parts to pick up the oil and 
throw it around the interior of the motor. Later, the sight feed de¬ 
vices that have been used for lubricating bearings of steam engines 
and other machinery were applied to the gasoline engine. These con¬ 
sisted essentially of a glass cup held in place between bronze castings 
to form the top and bottom of the oil container, respectively. The 
amount of oil supplied the bearing points was regulated by a suitable 
needle valve, and the oil supply could be observed through a small 


Lubrication , Carburetion and Ignition 210 

glass window in the bottom of the cup, before it reached the interior 
of the engine. Modern practice calls for a positive supply of the lubri¬ 
cating medium by mechanical means and the most effective of the 
methods of lubrication now in use are those in which the operator is 
depended on only to keep the oil container filled up. 

Sight Drip Feeds. —An example of the fitting employed to regulate 
the oil flow when the lubricant is supplied by gravity is clearly shown 
at Fig. 116. Fittings of substantially this design have received wide 
application on motorcycles. They are usually screwed directly into 
the bottom of the oil tank, and as that member is alwavs carried 
higher than the engine, when included in the fuel container, the oil 
will tend to flow by its own weight. The device consists of a simple 
casting member carrying at its lower end a small chamber adapted 
to receive a sight feed gauge glass through which the oil feed may be 
readily observed. The pipe connecting the sight feed fitting to the 
engine base is attached directly to the bottom of the chamber carrying 
the gauge glass. The oil enters the device through the opening in the 
bottom of the tank, and the amount of flow can be regulated within 
a wide range by the use of the oil feed regulating needle valve which 
also serves as a shut-off valve when lubrication is not desired. The 
oil collects in the globular portion of the casting and drips through the 
constricted opening above the sight feed gauge glass. 

Simple Splash System with Hand Pump. —While the cus¬ 
tomary manner of lubricating the first engines was by supplying the 
crank-case directly with oil, there were certain defects to this system 
that made it imperative to add some device for directing the oil to 
the engine base without need of the rider dismounting. On the earlier 
motorcycles, it was common practice to supply a small oil cup just 
below the oil tank that held a certain amount of lubricant. The 
arrangement was such that this cup could be filled from the main con¬ 
tainer, and the instructions of the manufacturers were usually ex- 

I plicit in stating that every eight or ten miles of average riding that it 
would be necessary for the rider to supply the engine base with 
another cup full of oil. This meant that it was necessary for the 
rider to dismount and fill the cup from the main tank before per¬ 
mitting its contents to flow to the engine interior. The next im¬ 
provement to be made was the addition of a hand-operated plunger 


220 


Motorcycles , Side Cars and Cyclecars 


pump to supply the oil, and this was usually placed convenient to the 
rider so it could be operated without stopping the machine. A popular 
location was directly at the side or in the interior of the oil container. 
This system of lubrication is used on a number of motorcycles, even 
at the present time, either alone or in combination with some form 
of a drip feed fitting. 



Fig. 117.—Types of Plunger Pumps Utilized in Forcing Oil to Engine 

Crank Case. 


The plunger pumps are of two general types, as shown at Fig. 117. 
That outlined at A has manual control of the oil flow while that at 
B has automatic control. In the former, a two-way valve is provided 
in the bottom of the pump chamber, the spigot of which can be placed 
in three different positions. When placed as shown, with the valve 
operating handle pointing straight down, the interior of the pump is 







































































































Lubrication , Carburetion and Ignition 221 

directly in communication with the oil container, and an upward 
stroke of the plunger will fill the pump barrel or cylinder with lubri¬ 
cant. When the pump plunger is nearly to the top of its stroke, the 
valve-spigot operating handle is moved around in the direction of the 
arrow, so that it lies parallel with the intake passage. Under this 
condition, the two-way valve spigot was moved around so that the 
oil in the pump barrel may be forced through the outlet pipe because 
the oil tank is shut off by the solid wall of the spigot. If the valve- 
operating handle is turned a half revolution from the position assumed 
when discharging lubricant from the pump barrel, both orifices, that 
at the bottom of the pump, as well as the intake from the oil tank, 
are shut off, and no oil will flow either to the pump or to the engine 
until the valve-operating handle is moved as indicated. The arrows 
show the direction of flow of the oil when the pump piston ascends. 

Another popular form of pump is shown at Fig. 117 -B, and one 
reason for its popularity is that it is automatic in action, and requires 
no other attention on the part of the rider than raising and depressing 
the pump piston. When the pump piston moves upward, it creates 
a partial vacuum in the pump barrel, and this lifts the inlet-check 
valve from its seating and permits oil to flow into the pump interior. 
As soon as the pump cylinder is full, the inlet-check valve is reseated 
by a suitable spring, and, as the pump handle is moved down, the 
pressure of the oil tends to keep the intake check more firmly seated. 
The other check valve, however, is installed so it will open under the 
influence of the oil pressure, and this permits the lubricant to flow 
from the pump to the outlet pipe. The action of a pump of this nature 
may be easily understood by remembering that the intake-check valve 
will open only when the piston is going up, while the outlet-check 
valve will leave its seat only when the piston is going down. 

Some trouble is apt to materialize in a pump of this character, 
owing to the check valves becoming clogged up by gum or wax in the 
oil, and if this occurs the pump will not operate satisfactorily. For 
this reason, the check valves are usually housed in such a way that 
they may be easily removed for cleaning. Those who favor the 
manually operated valve contend that the elimination of the check 
valve makes the action of the pump positive, and therefore best 
adapted to the requirements of the ordinary rider. 


222 Motorcycles , Side Cars and Cyclccars 

The oil injected into the engine base fills the crank-case to a certain 
height, as indicated at Fig. 118, and, as will be apparent, the revolving 
fly-wheel will pick up the lubricant and throw it about the interior 
of the engine liberally. The oil supply to the motor shown is by a 
hand-operated plunger pump which injects a charge directly to the 


ALUMINUf 

crank-casc 


PLAIN bronze: 
BUSHING.. 


Oil ENTERS/ 
HERE 


OIL PASSAGE' 


,01L PASSAGE 


PLAIN BROMZE 
BU5HI NG 



-CRANK-PIN 


ROLLERS TOR 
CONNECTING RODS 


Fig. 118 . —Application of Simple Splash System to Motorcycle Engine 

Lubrication. 


crank-case as well as by a drip-valve fitting connected beneath the 
timing gear case. 

This oiling system has given excellent satisfaction on a prominent 
machine, the Excelsior. Even though anti-friction bearings are used 
in the connecting rod big ends, every precaution has been taken to 
supply oil to the roller bearings in a positive manner. The lubricant 

















































































































Lubrication , Carbnrction and Ignition 223 

enters beneath the timing-gear case, and is directed to the main bear¬ 
ing shaft from which it is conducted to the crank-pin by a passage 
drilled in the fly-wheel web, and communicating with a similar 
passage in the crank-pin so the oil is discharged at the central point 
of the bearing. Before it can be thrown off by centrifugal force, it 
must lubricate the roller bearings at either side. The oil mist always 
present in the crank-case and cylinder interior lubricates the piston, 
cylinder walls and main bearings positively. ' 

Mechanical Oilers.-—The problem of gas engine lubrication has 
always been a vital one when plain bearings are used, and, while the 
simple splash system has the advantage of lack of complication, the 
motor is always operating in a state of either feast or famine as regards 
lubrication of parts. Main shaft bearings, cylinders, and all recipro¬ 
cating parts will receive plenty of oil by the splash system, providing 
the oil level is high enough so the fly-wheels will pick up the lubricant 
as they rotate. The connecting rod big ends, which are attached to 
a rotating member, and one that turns very fast at that, cannot 
receive adequate quantities of oil because they throw it off as fast 
as it collects between the surfaces, except in some engines where the 
oil is supplied to the connecting rod big ends first. The writer does 
not mean to imply that the rod ends do not get oil, but from the way 
they wear out and the condition of the surfaces, it is apparent that 
they do not get enough oil at all times. Then again, when one con¬ 
siders that this is the bearing that takes the greatest stress, and that 
the projected area of the bushing is seldom conducive to maintenance 
of an oil film, it is not strange that anti-friction bearings are being 
used so generally to replace big end plain bushings. 

One of the first lessons learned by automobile engineers was that 
oil must be supplied in a positive manner if connecting-rod bushings 
were to endure, so in all automobile engines designed for racing or 
other exacting work and in most pleasure cars, force-feed lubricating 
systems are employed, and the lubricant is directed to the bearings 
through passages in the crankshaft by pressure produced by some 
positively driven force pump. If this precaution is considered desir¬ 
able on automobile power plants, where bearing surfaces do not need 
to be restricted in size, and which operate at about half the speed of 
a motorcycle engine, then it is apparent that positive lubrication is 


224 Motorcycles , Sicfe rVu\<? o nd Cycle-car^ 

not only very desirable but indispensable in small, high-speed engines 
of the air-cooled forms used to propel motorcycles. 

The oil pump used on the Indian motorcycle, and the method of 
application are clearly outlined at Fig. 119. The phantom view shows 
the simplicity of the pump mechanism very clearly, as well as defining 
the method of reciprocating the plunger. A small worm gear is driven 



Fig. 119.—Mechanical Oil Pump Used on the Indian Motorcycles and 
Method of Application to the Power Plant. 


from the timing gear, through the medium of a small spur pinion on 
the end of the driving worm shaft that projects into the engine in¬ 
terior. This worm rotates a worm wheel that works the crank em¬ 
ployed to reciprocate the pump plunger. As the pump plunger is 
raised, oil flows in to fill the barrel through the intake which is coupled 
directly to the tank, and on the down stroke the oil is discharged 













Lubrication , Carburetion and Ignition 


225 


through the outlet-check valves to the front cylinder, from which it 
drips into the interior of the engine. The oil level in the engine base 
can be readily ascertained by a gauge glass or window in the side of 
the crank-case. The oil is supplied to the front cylinder to insure 
that that member will receive an adequate supply. The tendency of 
the fly-wheels as they rotate is to throw the oil into the rear cylinder 



rather than the front one, because that member is approximately in 
line with the oil spray as it is discharged tangentially from the rapidly 
revolving fly-wheel rim. This would result in the rear cylinder secur¬ 
ing better lubrication than the front one if no provision was made for 
directing the oil from the mechanical pump to the front cylinder. In 
most cases, a mechanical oil pump is supplemented by a hand-operated 






















































































226 Motorcycles , Side Cars and Cyclecars 

type which is used in emergencies when it is necessary to supply more 
lubricant than the pump will deliver, as in fast riding. 

The oiling system of a prominent English machine, the Royal 
Enfield, is outlined at Fig. 120. The oil is carried in the tank at the 
back of the seat-post tube, and one of two pumps fitted outside of the 
timing-gear case draws the lubricant from the tank to the engine. 
The second pump, called the expulsion member, forces the oil from 
the engine base back again into the tank. Obviously, as long as the 
engine is running, there is a continuous circulation of oil. The dia¬ 
gram clearly outlines the whole system and the path followed by the 
oil from the tank A to the engine and back again. The supply of 
lubricant is regulated by a needle valve B which has a knurled top, 
and from that point passes through a filter C along the suction pipe E 
to the induction pump H. This pump discharges into the hollow end 
of the crankshaft L, forcing the oil along this shaft through an 
aperture in the fly-wheel, into the crank-pin bearing, from which point 
it is distributed by centrifugal force to the other engine parts. The 
oil then drips back into a sump integral with the crank-case, and any 
excess which has not passed through the engine shaft also reaches 
this sump through a by-pass or release valve. The expulsion pump 
J draws the oil from the sump K and passes it back again to the tank 
through the return pipe D. A filter in the sump retains any residue 
contained in the oil, and insures that only clean lubricant will be 
pumped back into the tank. 

The lubricating system used in the four-cylinder Pierce motorcycle 
is somewhat similar, except that but one pump is utilized instead of 
two. This system is clearly shown at Fig. 121. The oil flows by 
gravity to the base of the crank-case, from an oil tank forming part 
of the large front frame tube, and passes through the working parts 
as it flows. This flow is rapid and is started when a valve at the top 
of the tank is given a quarter turn. As soon as the engine starts, a 
rotary pump of the gear type sucks the oil from the oil well or sump 
at the bottom of the crank-case and forces it through a discharge 
manifold into chambers in which the lower ends of the connecting 
rod dip. With this system it is necessary to shut off the flow of oil 
at the tank whenever the machine is stopped, in order to prevent 
flooding the motor. 


Lubrication , Carburetion and Ignition 


227 


ambit3 Jo 



au 1(3113 Jo _ 1 U 04 J 


Fig. 121.—Lubricating System Used in Pierce Four Cylinder Motorcycle Power Plant. 




























































































































228 


Motorcycles , Side Cars and Cyclecars 


A modification of this system is shown at Fig. 122 applied to a 
single-cylinder engine. The usual form of pump drive by spiral gears 
is employed to draw oil from the container or sump integral with the 
engine base, but it is discharged from the oil supply pipe into a 
passageway that communicates with the interior of a hollow crank- 
pin. From here, it passes through an oil tube attached to the connect¬ 
ing rod and lubricates the wrist pin. The oil thrown from the rapidly 
revolving fly-wheel lubricates the cylinder and piston walls thor¬ 
oughly. 

The lubrication system outlined at Fig. 115 insures that the bear¬ 
ings will receive copious oiling and is a form that has given excellent 
service on thousands of automobiles, as well as having been success¬ 
fully applied to four-cylinder motorcycle engines. The pump draws 
oil from a sump cast integral with the crank-case through a filter 
screen. The oil level in the crank-case proper is kept at a certain pre¬ 
determined height by an adjustable overflow pipe so the fly-wheels 
will pick up lubricant as they revolve, as in conventional systems. 
The advantage of the adjustable overflow is that this can be easily 
changed at any time to permit of more or less oil in the crank-case. 
For example, if the engine is to be run at high speeds, as in racing, the 
level can be made higher. When the machine is new, or after new 
rings have been fitted to the piston, it may also be desirable to furnish 
more oil than would be required under normal operating conditions. 
The standpipe adjustment can be readily altered to suit conditions. 

The gear pump discharges the lubricant at some pressure and this 
is piped to a point at the bottom of the bearing housing cap at the 
drive side, where it communicates with a groove in the crankshaft. 
This groove is connected to a drilled passage in the shaft by another 
hole drilled at right angles to that in the shaft. The passage extends 
through the fly-wheel to the crank-pin center, from which a discharge 
hole directs the oil to a point between the crank-pin ball bearing races. 
The centrifugal force assists in distributing the lubricant, and the 
crank-pin bearings receive all they need. The oil spray thrown off 
by the revolving crank-pin supplements that picked up by the fly¬ 
wheels, and all interior parts receive positive lubrication. As the oil 
may be kept to the correct level automatically to insure adequate 
lubrication by splash, the rider’s responsibility ceases when he has 


Lubrication , Carburction and Ignition 


229 



Fig. 122.—Mechanical Oiling System Applied to Single Cylinder 

Motor. 


placed sufficient good oil in the sump. He may even be relieved of 
this duty by having an oil tank attached to the sump in such a manner 
that oil will be automatically supplied by the air lock system. 

Lubricating Two=Cycle Engines. —An advantage of some 
moment that is obtained by the use of a two-stroke power plant is 
the very simple method of lubrication employed in which all pumps, 
















































































230 Motorcycles , Side Cars and Cyclecars 

sight feed or drip devices and piping may be eliminated. The method 
of supplying the lubricant consists merely of mixing a certain amount 
of oil with the gasoline by pouring it directly into the gasoline tank. 
Owing to the construction of a two-cycle motor, which decrees that 
the explosive mixture must go into the engine base before it can pass 
into the cylinder it is possible to supply oil in the manner indicated. 
The oil is not dissolved by the gasoline but still its viscosity or body 
is reduced to such a point that it will pass through the spray nozzle 
of the carburetor without any difficulty. It separates from the ex¬ 
plosive vapor in the engine base and condenses in the form of minute 
globules of oil on all interior parts of the engine. A certain amount 
of the condensing oil vapor finds its way to the bottom of the engine 
crank-case, and is distributed by the fly-wheel just as in other splash 
systems. The amount of oil used is approximately one-half pint per 
gallon of gasoline, i. e., if two gallons of gasoline were poured into the 
fuel tank, it would be necessary to add a pint of oil to insure that the 
engine would be adequately lubricated. The proportion may also 
be expressed as, one part of oil to sixteen parts of gasoline by volume. 

Attempts have been made to lubricate four-cycle engines in this 
manner, but have not been successful on account of the mixture being 
supplied directly to the cylinder interior instead of to the engine base. 
The oil deposited in the combustion chamber interfered materially 
with correct valve action and promoted carbonization and caused 
ignition trouble by short-circuiting the spark plugs. In the two-cycle 
motors, the oil is well separated from the mixture before the gas charge 
is transferred to the cylinder interior from the crank-case. 

Motorcycle Fuel, Its Derivation and Use. —The great advance 
of the internal combustion motor can be attributed more to the dis¬ 
covery of suitable liquid fuel than to any other factor. The first gas 
engines made, utilized ordinary illuminating gas as a fuel, and, while 
this is practical for use with stationary power plants, wherever it is 
available, such as the natural gas fields of the Middle West, or in 
cities and towns having a central gas producing plant, it is obvious 
that it could not be very well applied to portable self-propelling power 
plants used for cycle propulsion. When it was discovered that certain 
of the liquid fuels belonging to the hydro-carbon class, which includes 
petroleum and its distillates, benzol and benzene, which are coal tar 


Lubrication , Carburetion and Ignition 


231 


products and alcohol, could be carbureted or mixed with air to form 
an explosive gas, the gas engine became widely used as a prime mover 
for all classes of vehicles. 

The liquid fuels have the important advantage that a quantity 
sufficient for an extended period of engine operation can be easily 
carried in a container that will not tax the capacity of the engine, and 
that requires but comparatively little space in any out-of-the-way 
portion of the frame. When used in connection with a simple vapor¬ 
izing device, which mixes the liquid with sufficient quantities of air 
to form an inflammable gas, the fuel is automatically supplied 
to the engine without any attention being demanded from the 
operator as long as the supply in the tank is sufficient to produce 
a flow of liquid through the pipe joining the mixing device and fuel 
container. 

Up to date, the most important fuel used in connection with motor¬ 
cycle and automobile engines has been one of the distillates of crude 
petroleum, known generally to the trade as “gasoline.” This liquid, 
which is a clear white, very light-bodied substance, evaporates very 
rapidly at ordinary temperatures. This feature made it especially 
adaptable for use with the early forms of mixing valves, because it 
mixed so readily with air to form an explosive gas. Fifteen years 
ago, there were very few industrial uses for gasoline and it sold for 
less than five cents a gallon in some cases. During the past decade, 
the demand for it has increased by leaps and bounds, and it now sells 
for four times as much as it did when the gasoline engine was first 
introduced. 

The specific gravity of gasoline varies from sixty to seventy-six 
degrees, though very little of the latter is now obtainable except by 
special arrangement with the oil-producing company. It was formerly 
thought that gasoline any heavier than seventy-six degrees would not 
work satisfactorily in the cylinders of the gas engine, and, while this 
is true of the early crude and inefficient vaporizers, modem mixing 
devices have been evolved which handle gasoline of sixty-two degrees 
specific gravity and even heavier. The percentage of gasoline pro¬ 
duced from crude oil in proportion to the other elements is very small, 
and as the demand has increased to such proportions, the tendency 
of the producer has been to make gasoline heavier or of lower specific 


232 


Motorcycles , Side Cars and Cyclecars 



Fig. 123.—Showing Location of Fuel and Oil Containers on the Eagle Motorcycle. This Arrangement is 

Representative of Standard Practice. 

















Lubrication , Carburetion and Ignition 233 

gravity by distilling off some of the heavier oils with it to increase 
the bulk produced. 

Experiments are being tried with kerosene and alcohol in auto¬ 
mobile carburetors, but these fuels are not considered seriously in 
connection with the motorcycle, on account of the small fuel consump¬ 
tion of all motorcycle power plants. When a gallon of gasoline will 
suffice for 50 or 60 miles’ travel, fuel expense is not a serious item, even 
considering the present price of gasoline. 

How Fuel is Carried. —The conventional method of carrying both 
the fuel and lubricating oil is clearly shown at Fig. 123, which gives a 
view of the Eagle motorcycle with the side of the tank broken away to 
show its division into two parts. The larger portion serves as a con¬ 
tainer for gasoline and is connected directly to the float chamber of 
the carburetor by the gasoline feed pipe. The oil container also 
houses the plunger pump used to supply oil directly to the crank-case 
and is provided at the bottom with a drip feed of the type previously 
described. The location of the motorcycle fuel tank is practically the 
same on all machines at the present time, though in the early days, 
as can be very clearly understood by referring to the views of pioneer 
forms of motorcycles given in the first chapter, it was attached to the 
frame at any convenient point. The popular location was overhang¬ 
ing the rear wheel. At the present time, the tank is invariably placed 
above the motor, and, while most makers favor the detachable con¬ 
struction by which a removable tank is placed between the top frame 
tubes, some manufacturers incorporate the tank as part of the frame 
structure. This is true of the Schickel motorcycle, in which the tank 
is an aluminum casting that also has the steering head and suitable 
projecting lugs for anchorage of the frame tubes cast integral. In the 
Pierce motorcycle, the frame is made of large tubing, and this serves 
to contain the fuel and lubricating oil as well as forming the frame 
structure. While the fuel tanks are usually made of steel, they are 
either galvanized or copper or brass plated in the interior to prevent 
corrosion due to moisture or acids in the gasoline. The endeavor of 
most designers is to attach the tank to the frame in a positive manner, 
and yet have the tank retaining brackets or clips accessible so that 
member can be easily removed for repair if it becomes damaged. The 
best material for tanks is heavy gauge copper as it is easier to solder 


234 Motorcycles , Side Cars and Cyclecars 

than steel, and is not affected by moisture or other agents that would 
have a chemical action on steel. 

Principles of Carburetion Outlined. —Carburetion is a process 
of combining the volatile vapors evaporating from the hydrocarbons 
previously mentioned with enough air to form an inflammable gas. 
The amount of air needed varies with the character of the liquid fuel 
and some mixtures burn much quicker than others. If the fuel and 
air mixture is not properly proportioned, the rate of burning will vary, 
and either an excess of fuel or air will reduce the power obtained from 
combustion materially. The proportions of air and liquid needed 
vary according to the chemical composition of the liquid. 

Gasoline, which is that commonly used at the present time, is said 
to comprise 84 per cent carbon and 16 per cent hydrogen. Oxygen 
and nitrogen form the main elements of the air, and the former has a 
great attraction for the main constituents of hydrocarbon liquids. 
What we call an explosion is merely an indication that the oxygen of 
the air has combined chemically with the carbon and hydrogen of 
gasoline. In figuring the proper amount of air to mix with a given 
quantity of fuel one takes into account the fact that eight pounds of 
oxygen are required to burn one pound of hydrogen, and that two 
and one-third pounds of oxygen are necessary to insure the combus¬ 
tion of one pound of carbon. As air is composed of one part of oxygen 
and three and one-half portions of nitrogen by weight, for each pound 
of oxygen one needs to burn either hydrogen or carbon, four and 
one-half pounds of air must be allowed. About sixteen pounds of air 
must be furnished to insure combustion of one pound of gasoline, the 
hydrogen constituent requiring six pounds of air, while the carbon 
component needs ten pounds of air. 

Air is not usually considered as having much weight, but at a 
temperature of 62 deg. Fahr. fourteen cubic feet of air will weigh 
a pound. Two hundred cubic feet of air will be needed to burn a 
pound of gasoline according to theoretical considerations. The ele¬ 
ment nitrogen, which is the main constituent of air, is a deterrent to 
burning as it does not aid combustion or burn itself. Therefore, it 
is usual practice to provide four hundred cubic feet of air to each 
pound of gasoline. Mixtures varying from one part of gasoline vapor 
to from four to thirteen parts of air can be ignited, but the best 


Lubrication , Carburetion and Ignition 235 

results are obtained when five to seven parts of air are combined with 
one of gasoline vapor. This mixture produces the most rapid com¬ 
bustion, the highest temperature, and, consequently, the most 
pressure. 

What the Carburetor is for. —Any device which will supply 
gasoline and air in measured quantities so inflammable mixtures of 
the proper proportions will be supplied the engine is called a “car¬ 
buretor.” In its simplest form, a carburetor would consist of a pipe 
open at one end for the admission of air, and joined to the cylinder at 
the other, and having a spray nozzle or opening through which 
gasoline could be injected into the air stream placed at some inter¬ 
mediate point in the pipe between the air inlet and the gas outlet to 
the cylinder. 

Early Vaporizer Forms. —The surface carburetor was the first 
device to be used in combining air with gasoline to form an explosive 
vapor. Before the motorcycle or automobile became popular, the 
gasoline available was of very high volatility, i. e., it evaporated much 
more readily than the heavier fuels available to-day. A typical sur¬ 
face carburetor, such as used on one of the earliest practical motor¬ 
cycles, the Wolfmueller, is shown at Fig. 124. The operation of this 
device is easily understood. The carburetor was filled with fuel to a 
definite height which was so regulated that the surface of the liquid 
was just below the lower main air pipe opening. The air entered 
through a funnel-shaped member which deflected it over the surface 
of the fuel. Here it became mixed with the vapor given off by the 
volatile liquid and the mixture passed through a safety screen to a 
mixing valve on top of the carburetor. The vapor given off was very 
rich, and, in order to dilute it, extra air was admitted through an 
auxiliary air cone attached to the mixing valve. The gas supply to 
the engine was regulated by a simple throttle as was also the amount 
of air from the auxiliary air entrance. A separate throttle was pro¬ 
vided to regulate the quantity of gas supplied as the only function of 
the mixing valve or chamber was to regulate the quality of the gas. 

Another form of surface carburetor that received wide application 
on the early motor tricycles of De Dion-Bouton manufacture is out¬ 
lined at Fig. 125, A. In action, it is very similar to that previously 
described, except that it was improved in some details. For example, 


236 


Motorcycles , Side Cars and Cyclecars 


a plate was attached to the bottom of the main air supply tube, and 
this insured that all the air currents would pass over the surface of 
the liquid and become saturated with vapor. It was necessary to use 
a mixing valve at the top of this carburetor, in order to dilute the rich 
vapor, so as to secure an explosive mixture of proper proportions. 

The simple form that 


Auxiliary Air 
E.nfcranc* 


f^Uin Air 
Inlet 


Safety 

Screen 



vel 


Fig. 124.—The Wolfmueller Surface Vapor¬ 
izer, One of the First Practical Devices 
for Carbureting Volatile Hydrocarbons,. 


is really the parent of 
our present float feed 
carburetors is shown at 
Fig. 125, B. In this, the 
gasoline was supplied 
from a container to a 
fuel inlet on the side of 
the main casting. A re¬ 
gulating needle valve was 
placed in the passage 
that provided communi¬ 
cation from the fuel in¬ 
let to the jump valve 
seat. The air entered 
below the jump valve 
which was normally 
spring retained against 
the seating so that the 
mixing device was di¬ 
vided into two parts, one 
below, the other above 
the valve. As the valve 
covered the spray open¬ 


ing, no gasoline could flow into the mixing device as long as 
the valve was held against its seat by the spring. The suction 
of the piston in the engine cylinder raised the jump valve from its 


seat, and at the same time the partial vacuum caused the gasoline 






to spray out of the opening and mix with the current of air drawn in 
through the main air inlet and into the upper portion or mixing 
chamber of the device. The amount of liquid supplied the 
mixture was regulated by the needle valve, while the proportion of 






























Lubrication , Carburetion and Ignition 


237 




Mixture 
Outlet 
,G&5 


A/* 


Plate 



Mixing 

Chamber 

GasOutlet Mixture Regulation 
Mixture Outlet J r pValve \ ' Throttle 

,jprin£ 

J 

■'"V" « __ / 

r 


Spray 

Openmd 





Main Air 
Inlet 


B 


Regulatings 
. Needle 
Fuel 
Inlet 



Shut-Off Needle 


Wicks 


Fuel Chamber 


Fig. 125.—Early Types of Gasoline Carburetors. A—De Dion Bouton 
Surface Vaporizer. B—Simple Spraying Device With Automatic 
Jump Valve. C—Diagram of Wick Carburetor. 


air could be altered at will by limiting the movement of the jump 
valve. 

A third form that received limited application is known as “the 
wick feed carburetor,” and is illustrated at C, Fig. 125. In this 
device, the liquid was drawn to the top of the container by the 
capillary attraction of the wicks, and as the top of these were brushed 
over by the main air current, the vapors given off were mixed with it 
to form an explosive gas. The mixture proportions were regulated 












































































238 


Motorcycles , Side Cars and Cyclecars 


by a simple shutter which could be swung on an arc so that it could 
be brought very close to the wicks or moved away. This shutter 
deflected the entering main air current against the wicking, and when 
in its uppermost position, practically no air would enter the mixture 
without passing over the surface of the wicks and becoming saturated 
with fuel vapor. When the shutter was in an intermediate position, 
part of the entering air stream would pass over the wicks while the 
remaining portion would flow directly into the column of gas and 
dilute it if too rich. The fuel inlet from the tank to the fuel chamber 
of the mixing device was controlled by a shut-off needle and the 
amount of mixture supplied the engine could be varied by a simple 
throttle of the damper type. 

Defects of Simple Vaporizer Forms.—The simple mixing valve 
forms have disadvantages of some moment, the main defect being 
that they are somewhat erratic in action, and that the mixture cannot 
be as well regulated as when float feed carburetors are used. While 
the primitive forms gave fairly good results with high grade gasoline, 
they do not carburet the lower grades of fuel used to-day properly, 
and do not supply enough gas of proper consistency for the present 
types of engines. The most efficient modern power plants utilize 
float feed carburetors instead of simple mixing valves. The ad¬ 
vantage of the float construction is that the gasoline is maintained 
at a constant level regardless of engine speed. In the simple forms 
of generator valves in which the gasoline opening is controlled by a 
poppet valve, a leak in either valve or valve seat will allow the fuel 
to flow continuously whether the engine is drawing in a charge or not. 
During the idle strokes of the piston when there is no suction effect 
exerted to draw in gasoline vapor, the liquid fuel will collect around 
the air opening, and when the engine does draw in a charge it is 
excessively rich because it is saturated with globules of liquid fuel. 

With a float feed construction, a constant level of gasoline or other 
fuel is maintained at the right height in the standpipe, and will only 
be drawn out of the jet by the suction effect of the entering air stream. 
The objection to the simple surface or wick feed is that the tendency 
is to draw off only the more volatile constituents of the fuel, and that 
after a time the heavier elements included in gasoline will remain in 
the vaporizer and will not be changed to gas. Obviously the engine 


Lubrication , Carburetion and Ignition 239 

is not capable of utilizing all of the fuel. With a float controlled 
spray nozzle, the spray is composed of all the constituents of the 
liquid, and the lower grade portions that are mixed with those having 
higher evaporation points are drawn into the cylinder and burnt 
instead of settling to the bottom of the carburetor. 

Elements of Carburetor Design. —The float-feed carburetor, 
with concentric float and mixing chambers, is the standard American 
type, and preference is given to automatic carburetors. In England, 
the practice is different, as the carburetors have separate float and 
mixing chambers for the most part, and are manually controlled 
instead of having automatic compensation for speed variation as is 
general in this country. In float-feed carburetors, the principle of 
mixing the gasoline vapor and air is the same as in the early forms 
of mixing devices, but the method of fuel supply is different. The 
device consists of two parts, a float chamber and a mixing chamber. 
The standpipe in the mixing chamber is connected to the float 
chamber, and the arrangement is such that the level of liquid in the 
float chamber is kept to a height equal to that of the spray nozzle. 
The fuel pipe from the tank or main container is coupled to the inlet 
pipe of the float chamber, and the opening is closed by means of a 
needle point carried by a hollow metal or cork float. The length of 
the needle is such that its point shuts off the gasoline supply when 
the level of gasoline in the float chamber coincides with the top of 
the standpipe.' Whenever the fuel is drawn out of the float chamber 
sufficiently fast so the level is reduced, the float will sink with the 
decreasing liquid, and the passage in the fuel supply pipe is opened, 
allowing gasoline to flow into the float chamber until the liquid is at 
the proper height. Just as soon as the proper level is reached, the 
float and the needle it actuates are moved until the valve shuts off 
the flow of gasoline from the tank. 

The concentric float chamber feature insures a constant level of 
fuel at the nozzle. When the nozzle is carried at one side of the float 
chamber, if the carburetor tilts, as is possible when climbing or 
descending a grade, if the float chamber is higher than the nozzle, the 
carburetor will flood. If conditions are reversed, the level of fuel in 
the spray nozzle will not be high enough, and the mixture will be too 
thin. With the spray nozzle placed at the central point of the device, 


240 


Motorcycles , Side Cars and Cyclecars 


no reasonable amount of tilting will change the height of the liquid 
at that point, and a mixture of constant proportions is insured under 
all abnormal as well as normal operating conditions. The advantages 
of this construction do not seem to be properly appreciated by 
European designers, though generally accepted by American en¬ 
gineers. 

Features of Automatic Carburetors. —The simple form of float 
feed spraying carburetor has disadvantages that made improvements 
in construction necessary before it became really efficient. One of 
these was that as the engine speed increased, the suction effect aug¬ 
mented in proportion, and as more gasoline was sprayed into the mix¬ 
ture because of the higher degree of vacuum created in the cylinder, 
the mixture became too rich at high speed. This is the main reason 
for the introduction of the modern automatic carburetor, such as 
shown at Fig. 128. In this device, the needle valve is mounted concen¬ 
tric with the float, i. e., the mixing chamber passes through the center 
of the carburetor, while the bowl, in which a horse-shoe shaped float 
is placed, surrounds the mixing chamber. The air pipe is constricted 
around the spray nozzle in order to get the proper air speed to insure 
positive suction of liquid at low engine speeds. At high engine speeds, 
when the mixture would be too rich in the simple form of carburetor, 
an automatic auxiliary air valve, which is carried to one side of the 
mixing chamber, opens and admits air to the mixture to dilute it. 
In the English carburetors, it is necessary to regulate the air supply 
with every change in engine speed, as it is believed that this is the 
only way to secure maximum economy. An automatic carburetor 
obviously must give average results, and intelligent hand regulation 
means that the best mixture for any engine speed can be selected by 
trial instead of approximated by an initial setting of the carburetor. 

Typical Motorcycle Carburetors. —One of the most popular of 
all motorcycle carburetors, and the type which has undoubtedly re¬ 
ceived the widest application because it has been a standard fitting 
on the Indian motorcycle since its inception, is illustrated at Figs. 
126 and 127. The external view at Fig. 126 will assist in making 
clear the action, while the arrangement of internal parts can be 
readily ascertained by consulting the sectional drawing at Fig. 127. 
This design originated through a desire of its inventor, Oscar Hed- 


Lubrication , Carburetion and Ignition 241 


strom, who was then building motor-pacing tandems, to eliminate 
the continual shifting of an air valve every time the throttle was 
moved, as was true of the early carburetors and even present-day 
foreign designs. The Hedstrom was the first automatic carburetor 
to receive general approval, and was also one of the first to incorporate 
the concentric arrangement of float and mixing chambers that is so 
common at the present time. The automatic compensation feature 

was secured by a conical 
sleeve working in the 
mixing chamber, and ac¬ 
tuated through a suitable 
connecting rod and crank 
arrangement attached to 
the throttle barrel. A 
manually regulated air 
shutter was provided to 
get a correct mixture 
when starting the ma¬ 
chine, and when this has 
been set to provide a 
proper running mixture, 
the carburetor automat¬ 
ically took care of mix¬ 
ture variations and prop¬ 
er compensation was 
made between the air and 
the gasoline as the throt¬ 
tle was moved. In the 
latest form of Hedstrom 
carburetor, a pilot jet is provided in a separate mixing chamber which 
facilitates starting the motor and insures steady running at low engine 
speed. This carburetor was one of the contributing causes that made 
the Indian machine superior to the earlier forms of foreign and domestic 
manufacture, because it provided a much better and more uniform 
mixture than the mixing valves and surface vaporizers that were 
generally employed, and permitted greater engine speeds and flexi¬ 
bility. 



Fig. 126.—The Hedstrom Automatic Car¬ 
buretor Used, on Indian Motorcycles. 









242 


Motorcycles , Side Cars and Cyclecars 



Fig. 127.—Sectional View Showing Interior Arrangement of Hedstrom 

Automatic Carburetor. 


Sectional views showing the construction of the Schebler motor¬ 
cycle carburetor are presented at Fig. 128. This is a concentric form, 
and a feature of merit is the method by which the fuel supply is aug¬ 
mented as the throttle is opened. The adjusting needle valve is 
carried on a bell crank which can be rocked by a cam forming part 
of the throttle linkage. This cam is so arranged that as the throttle 
is opened a spring, bearing against the bell crank member, will raise 
the needle from its seating in the spray nozzle and permit more gaso¬ 
line to enter the mixture. The auxiliary air supply is regulated by 
altering the tension of the spring used to keep the air valve seated. 
In the Hedstrom carburetor, the float is of hollow metal, whereas in 
the Schebler a cork float is utilized. The method by which the float 



































































































Lubrication , Carburetion and Ignition 243 

shuts off the flow of fuel from the tank when it reaches the right 
height in the float chamber is practically the same in all carburetors. 
A lever of the first class transmits the upward motion of the float to 
the needle, which moves in the opposite direction, and which shuts 
off the fuel inlet when the liquid reaches the proper level in the float 
chamber. 

In the Kingston carburetor, shown at Fig. 129, the concentric float 
and mixing chamber are retained, as this construction may be said to 
represent standard American practice. A feature of the device is the 
use of a series of balls of varying weight to control the auxiliary air 
ports. As the throttle is opened, and the suction becomes greater, 






TVwoWe 



Flo&t 
Mam 

a£ v * w ;& 


PUxino 
Chamber 



Fue\ Tntat 


? ra Y 


NorzA< 


Fig. 128.—Schebler Motorcycle Carburetor. 










































































244 


Motorcycles, Side Cars and Cyclecars 



Fig. 129.—The Kingston Automatic Carburetor With Auxiliary Air 

Control by Ball Valves. 


the balls open progressively and admit more air to the mixture. In 
this carburetor, no provision is made for altering the amount of 
auxiliary air under the control of the rider, but, instead, mixture pro¬ 
portions are altered by a needle valve which determines the amount 
of fuel sprayed from the stand pipe. 

At Fig. 130, sectional views of the Breeze carburetor are depicted 
and in this form automatic regulation of the fuel supply is possible, 
as the throttle is opened because of a direct mechanical interconnection 
between the throttle lever and the regulating needle valve, as outlined 
at Fig. 131. The auxiliary air supply is regulated by means of a flat 
seated air valve provided with the usual adjustable reseating spring. 







































































Lubrication , Carburction and Ignition 


24 5 



Fig. 130.—Sectional Views Showing Construction of Breeze Motorcycle Carburetor. 





































































































246 


Motorcycles , Side Cars and Cyclecars 


The manner in which the mechanical interlock between the needle 
valve and throttle lever works can be readily determined by observing 
the relative positions of the numbers on the regulating needle valve 
top with the throttle in the closed and opened position. It will be 
observed that in the closed position, the figure 1 is approximately 
in line with the center fine of the carburetor, whereas when the throttle 
is opened the needle valve has opened sufficiently so the numeral 3 
now registers with the carburetor center line. Practically all car¬ 
buretors include a “tickler” or primer provided so the float can be 
depressed several times to cause gasoline to overflow the spray nozzle 
and thus provide a rich mixture for starting. 

Foreign Carburetor Designs. —Carburetors of English and 
French design are considerably different from those of American 
manufacture because the automatic feature is seldom utilized, and 
also because the float chamber is usually distinct from and set at one 
side of the mixing chamber. European carburetors are not only more 
bulky than our American forms but would not meet with much favor 
in this country on account of the constant manipulation of the air 
valve necessary every time the throttle is moved. 

The Longuemare, a popular French carburetor, is shown at Fig. 
132, while two representative English types are outlined at Fig. 133. 
The feature of the Longuemare carburetor is the design of the spray 
pipe which includes an ingenious method of regulating the quantity 
of fuel spray by a conical plug provided with a number of passages 
so the fuel is atomized in a number of fine streams instead of one large 
stream as is the case when a spray nozzle having but a single central 
opening is used. The small streams are more quickly vaporized and 
are more easily absorbed by the entering air than the one large stream 
would be. The amount of gasoline is varied by changing the depth 
or number of the passages cut on the face of the tapered plug. If the 
mixture is too rich, one or more of the grooves may be filled in with 
solder, whereas if it is not sufficiently rich, the grooves provided may 
be made deeper and thus allow more liquid to flow into the mixture. 
The form shown is provided with a heating jacket and when used, in 
connection with an air-cooled motor, a portion of the exhaust gas is usu¬ 
ally deflected through this chamber to furnish heat. It is not custom¬ 
ary to provide these heating chambers on motorcycle carburetors. 


Lubrication , Carburetion and Ignition 247 

The English carburetors shown at Fig. 133 are practically the same 
in principle, the only difference being in details of construction. For 
example, that on the left employs a counter-weighted float arrange¬ 
ment, while that at the right is considerably simpler because the float 
needle which regulates the main fuel inlet is attached directly to the 
float and moves in the same direction. The method of auxiliary air 
regulation, and also the throttle control in the device at the left, is 
by semi-circular slides which are normally pressed down by springs, 


THROTTLE OPEN THROTTLE CLOSED 



I- - ----— 

Fig. 131.—Top Views of Breeze Motorcycle Carburetor, Showing 
Mechanical Interlock Between Throttle and Mixture Regulating 
Needle. 

so as to regulate the size of the extra air opening or that leading to 
the engine. These slides are adapted to be worked from the handle 
bars through Bowden wire control. In the device at the right, con¬ 
centric slides are utilized to regulate the proportion of air admitted 
the mixture, and the quantity of gas supplied the motor. The outer 
slide is the member controlling the extra air, while the inner member 
regulates the supply of gas. In the American carburetors having a 




































248 


Motorcycles , Side Cars and Cyclecars 


needle valve pointing directly into the spray nozzle, an advantage of 
some moment is gained by breaking up the entering fuel stream into 
a spray. In the English device, at the right of Fig. 133, a small spray¬ 
ing cone is attached to the throttle slide that is intended to perform 
the same function. 

It is desirable to interpose some form of strainer or filter in the 
gasoline line between the tank and the carburetor in order to prevent 


Primer 

i piu <? x 

Needle 


Float 





f--^ 

i — •• 

!- 

^ j*- 

s' ^ 


fi ■ /[ * F\ 


-ffri III "1 




Throttle 


1 11 


r 


/ 

Fuel Inlet 



'Mixture 

Outlet 

Water 
Oacket 

Inlet 


Hot Water 

Intake 


Spray Pipe 


Fig. 132.—The Longuemare Carburetor, a Representative French 

Design. 


dirt or water from reaching the interior of that device. Two typical 
straining devices are outlined at Fig. 134. In both of these, a gauze 
screen is used to separate the dirt from the gasoline, and a settling 
chamber is provided in which all dirt or water collects instead of 
flowing to the carburetor. Suitable drain cocks are provided so the 
settling chamber may be cleaned out when necessary. 






























































































Lubrication , Carburction and Ignition 


249 



Fig. 133.—Sectional Views of Typical English Carburetors, Showing the Placing of the Float Chamber 
at One Side of the Mixing Chamber and the Air Regulation by Hand Operated Valves. 












































































































































250 


Motorcycles , Sicfe GW,? and Cyclecars 


Another point that needs to be carefully observed to secure proper 
carburetion, in addition to the design of the vaporizer, is to proportion 
the intake manifold so the gas flow will not be obstructed and the 
charge will reach the cylinders promptly. The inlet manifold used 
on motorcycles is very simple when applied to twin-cylinder engines 
and in most cases endeavor is made to have the carburetor attached 
to the inlet pipe in such a way that it may be readily detached without 
disturbing the remainder of the piping, or the inlet pipe itself is fitted 
with suitable threaded connections at the ends so it can be removed 
from the valve chambers. Various forms of inlet pipes used in con- 



Fig. 134.—Strainers of Breeze Design to be Interposed Between 
Gasoline Tank and Carburetor for Preventing Passage of Water 
or Sediment to the Mixing Device. 


nection with twin-cylinder engines are shown at Fig. 135. At A, the 
inlet valve dome castings have extensions to which a very short 
fitting carrying the carburetor is attached. At B, the manifold is a 
one-piece member attached to the inlet valve domes by easily remov¬ 
able retaining couplings. The construction at C is similar to that 
shown at B, except that it has a more pronounced curvature. In the 
manifold shown at A, the intake pipe is straight, whereas in those 
shown at B and C the gas passages are laid out with curves that are 
intended to provide an easy path from the carburetor to the cylinder 


































Lubrication , Carburetion and Ignition 


251 



- -- - 

Fig. 135.—Design of Inlet Manifold for Twin Cylinder Motorcycle 
Power Plants. A—De Luxe. B—Emblem. C—Monarch. D—Fiel- 
bach. 

interior. The form shown at D is also laid out in curves, but instead 
of the manifold rising from the carburetor to the valve chamber the 
pipes leading from the central fitting to which the carburetor is 
attached have a pronounced drop to the top of the cylinder. 

The design of a suitable inlet manifold for a four-cylinder engine 
is one that calls for considerable judgment, as it is not practical to 
use the same type of a manifold as is employed on automobile motors 
owing to lack of space, and also because the carburetor must be 
carried at one end instead of at the side of the engine. It is possible 
to design an inlet manifold for a four-cylinder automobile motor that 
will give practically the same length of passage from the carburetor 
to any one of the four cylinders, and each cylinder receives the same 
quantity, and presumably the same quality of explosive mixture. As 









252 Motorcycles , Side Cars and Cyclecars 

an example of a four-cylinder manifold, that used on Pierce engines 
is shown at Fig. 136. Viewed from the exterior, it would appear that 
the intake pipe was a simple tubular member having a branch leading 
to each cylinder, but when one examines the sectional view it will be 
seen that a partition wall is placed in the interior, and that this com¬ 
pensates in a degree for the difference in distance between the inlet 
valve of the first cylinder and the carburetor carried at the rear of 
the motor. 



Fig. 136.—-Inlet Manifold for Four Cylinder Motorcycle Power Plant. 


Typical Mufflers and How They Operate.— After the charge of 
gas compressed in the cylinder has been ignited, and even when the 
piston reaches the bottom of its stroke, the exhaust gas still has con¬ 
siderably more pressure than the atmosphere. It is said that the 
pressure of the exhaust gases discharged through the exhaust valve 
when that member is first opened is about 40 to 45 pounds, and if 
the gas is discharged directly into the air, the vibration caused by the 


















Lubrication , Carburetion and Ignition 253 

violent ejection of the gases produces a noise comparable to a gun¬ 
shot. The function of the muffler is to silence the exhaust by per¬ 
mitting the gas to expand to approximately atmospheric pressure 
before it reaches the air. One of the difficulties incidental to muffler 
design is to provide a form that will be effective as a silencer, and yet 
not offer appreciable resistance to the flow of the gases as this pro¬ 
duces a back or nega¬ 
tive pressure on the pis¬ 
ton top when rising on 
the exhaust stroke 
which reduces the pow¬ 
er output of the engine. 
This problem is not a 
difficult one for auto¬ 
mobile designers to 
solve, because they 
have plenty of space 
available and can make 
the expansion cham¬ 
bers large enough so 
that there is ample 
space for the gas to 
expand before leaving 
the muffler interior. It 
is only necessary to pro¬ 
vide an expansion cham¬ 
ber of a little more than 
three times the cubical 
capacity of one of the 
cylinders, and to break 
up the entering gas stream to facilitate its expansion, and one obtains 
a very effective muffler that offers no appreciable back pressure. In 
motorcycle practice, it is necessary that the muffler should be small 
and not occupy much space, so it is seldom that the motorcycle muffler 
will have more than the cubical capacity of the cylinder to which it is 
applied. When one considers that the gases are being discharged into 
a silencer at a velocity of 6,000 to 7,000 feet per minute, with the 


Cylinder 


Valve Cap 
Exhaustive 


Exhaust 

^ Pip* 



Fig. 137.—Showing the Use of Muffler to 
Receive and Silence the Exhaust Gases 
Before They are Discharged to the 
Atmosphere. 






































254 


Motorcycles , Side Cars and Cyclecars 


motor running 2,000 revolutions, it will be apparent’that it ’is a 
problem of some magnitude to dissipate the current of gas rapidly 
enough to break up its acoustic powers without producing a negative 
pressure against the piston. 

The construction of a typical motorcycle muffler of English design 
is shown at Fig. 137. The principle of silencing involved is to break 
up the gas into a large number of small streams by the medium of 
perforated baffle plates through which the gas must pass before it is 
discharged to the air. The general practice is to provide one muffler 
for both cylinders because but one is exhausting at a time. Some of 
the foreign motorcycle builders provide a separate muffler for each 
cylinder as indicated at Fig. 138. The somewhat novel and effective 
silencing arrangement used on Iver-Johnson motorcycles is shown at 
Fig. 139. This consists of what is practically an extension of the 
exhaust pipe, perforated with a large number of holes. It is said to 
be reasonably silent, and as there are no baffle plates interposed to 
hinder the flow of gas, it offers minimum back pressure. 

An efficient muffler of American design is shown in the sectional 
view at the bottom of Fig. 139. In this, the gas enters a large chamber 
which is separated into six compartments by four baffle-plate members 
and an inner cylinder. Before the gas can pass out, as indicated by 
the arrows, it must first pass through the perforated baffle plates into 
an intermediate expansion chamber which communicates with a con¬ 
centric cylindrical expansion chamber extending the length of the 
muffler. This has suitable perforations in its wall. 

The endeavor of designers is to make mufflers that can be easily 
taken apart for cleaning which is a desirable feature in view of the 
oily character of the exhaust gas discharged from the average motor¬ 
cycle power plant. In the form at Fig. 139, the various components 
are held together by a through bolt and the muffler can be easily dis¬ 
assembled by loosening one of the clamping nuts at the end of the 
bolt. The various parts may be removed from the main head fitting, 
and after all deposits of oil and carbon have been removed, it is a 
simple matter to replace the perforated cones around the central ex¬ 
pansion chamber and clamp these members between the muffler heads 
by the retaining bolt. If cleaning is neglected, the openings in the 
baffle plates may become choked with carbon, and, as the area of 


j Lubrication , Carburetion and Ignition 


255 


the passages is decreased, considerable back pressure will be present 
which may cause the engine to overheat. 

Use and Abuse of the Cut=Out Valve. —Many mufflers are pro¬ 
vided with a cut-out valve designed so that gas can be discharged 
directly from the exhaust pipes to the outer air instead of into the 
muffler interior. It is an advantage to include a cut-out with the 
muffler as this can be opened when full efficiency of the engine is 
desired as in speed work or hill climbing. The cut-out also affords an 


GyUndfcYS 


P\v)<g 


Jnlet Valve 
Spaced Plug 


Magnate 



Pi 


E.*V\akV*k 

Pipe 


et* 


fAu^ler 


Fig. 138.—Premier Motorcycle Power Plant Which Utilizes Two 

Mufflers, One for Each Cylinder. 


opportunity to judge the regularity of engine running, because the 
explosions can be heard easily with a cut-out opened. While the cut¬ 
out is a useful fitting, it has been abused in many instances by riders 
who leave it open in passing through towns or when using the motor¬ 
cycle in traffic. In fact, the practice of running with an open muffler 
has been so general in the past that the impression conveyed to the 
layman has been that in silence of operation a motorcycle and a rapid 


















256 


Motorcycles , Side Cars and Cyclecars 


fire gun are synonymous. Practically all of the motorcycles on the 
market to-day are provided with effective and efficient silencers, and 
there is no excuse for running with a cut-out open in average touring 
work. Some manufacturers are successfully combating the open 
muffler evil by eliminating the cut-out fitting altogether which makes 
it imperative that all exhaust gases be discharged through the muffler. 
The arrangement of the cut-out and muffler of the Excelsior motorcycle 
is clearly outlined at Fig. 140. The muffler head has the branches, in 



I 


Fig. 139.—Typical Exhaust Silencing Devices. 







































Lubrication , Carburetion and Ignition 257 

which the exhaust pipes are secured, cast integral, and, at one side of 
the head, an opening is provided in this casting which is closed by a 
suitable damper or shutter easily worked by a small lever or crank 
to which it is attached. This crank can be moved easily with the 
foot, and can be opened or closed while riding as conditions dictate, 
and will stay in either the open or closed position. 

How Compressed Gas is Ignited. —When the gas engine was 
first developed, the compressed gas was exploded by means of a naked 
flame which was permitted to communicate with the combustion 



Fig. 140.—Method of Utilizing Exhaust Cutout Valve in Connection 

With Excelsior Muffler. 


chamber interior by means of a slide valve which moved at the proper 
time to permit the flame to ignite the gas back of the piston. This 
system of ignition was practical only on the primitive gas engines 
where the charge was not compressed to any degree. When it became 
desirable to compress the gas before firing it, the hot tube system of 
ignition was used. This method involved the use of an incandescent 
platinum, porcelain or nickel tube in the combustion chamber, the 
tube or ignitor being kept in a heated condition by a flame burning 
in it. Another method depends upon the property of gases firing 





258 Motorcycles , Side Cars and Cyclecars 

themselves if compressed to a sufficient degree, provided that a cer¬ 
tain amount of heat was stored in the cylinder head to insure com¬ 
plete vaporization of the gas, and help produce the proper kindling 
temperature. 

Practically all of the gas engines in use at the present time, except 
•those employed for stationary power that operate on the Diesel sys¬ 
tem, utilize electrical ignition systems. In all motorcycle and auto¬ 
mobile power plants, the compressed gas is exploded by a minute 
electric arc or spark in the cylinder, the current for which is produced 
by some form of chemical or mechanical generator of electricity. The 
early forms of ignition systems had a disadvantage in that they were 
not flexible and could be used successfully only on constant speed 
engines. None of these methods are practical in connection with 
motorcycle power plants because they do not permit the flexible 
engine action that is so desirable and necessary. v. 

While electrical ignition systems are somewhat more complicated 
than the other simpler types, they are the most efficient, and as their 
peculiarities are now generally understood, there is no difficulty in 
applying them successfully. Two forms of electric ignition systems 
have been used, the most popular being that in which a current of 
electricity under high potential or pressure is forced to leap an air 
space between the points of a spark plug which is screwed into the 
cylinder. The other system, which is used to a limited extent on 
marine engines, is known as the low tension system because a current 
of comparatively low voltage is utilized instead of the high pressure 
current used in the more popular systems. Whereas the spark is pro¬ 
duced in the high tension system by the current heating up the air 
particles between the points of the spark plug, it is produced in the 
combustion chamber when the low tension method is employed by 
moving electrodes which come in contact with each other, and which 
produce a spark as they separate. 

The essential elements of any electrical ignition system are: First, 
a simple and practical method of current production; second, suitable 
timing apparatus to cause the spark to occur at the right point in the 
cycle of engine action; third, some form of igniter to produce the spark 
in the combustion chamber; fourth, apparatus to transform the low 
tension current obtained from batteries or dynamo to one of greater 


Lubrication, Carburetion and Ignition 259 



Ground 


Fig. 141.—Diagram Showing Battery Ignition Systems for Single 

Cylinder Engines. 



























































































260 


Motorcycles , Side Cars and Cyclecars 


value before it can produce a spark in the cylinder; and fifth, suitable 
wiring, switches and other apparatus to convey the current produced 
by the generator to the auxiliary apparatus, and from these to the 
spark-producing member in the cylinder head. 

There are two common means for obtaining the electrical current 
used to produce the spark in the cylinder, one of these depending on 
a chemical action, the other an electro-magnetic action. The first 
class includes the various forms of primary and secondary batteries, 
while the second group includes the various mechanical appliances, 
such as dynamos and magnetos. The simplest method of current 
generation is by means of a simple chemical cell, generally known as 
the “dry battery.” These belong to the primary cell class because a 
current of electricity is generated by the oxidation of one of the ele¬ 
ments of which the cell is composed by the electrolyte. Any primary 
battery consists of three main elements: First, a plate of some 
material which will be acted on by the electrolyte; second, an elec¬ 
trolyte which may be a solution of a salt or acid in water, which will 
have a chemical affinity for the active element; third, a neutral plate 
which serves to collect the electricity produced by the chemical com¬ 
bination of the electrolyte and active elements. 

The dry battery is so called because the electrolyte is in the form of 
a paste instead of a liquid. The dry cell consists of a zinc can filled 
with electrolyte and a depolarizing chemical in the center of which a 
carbon rod or plate is placed. The function of the depolarizer is to 
keep the cells active for a longer period than would be the case if only 
a simple electrolyte was used. The zinc can serves as a container for 
the electrolyte and also forms the active member. The carbon rod 
is the neutral or collecting member. A terminal is attached to the 
zinc can and is known as the negative, commonly indicated by a 
minus sign thus (—) while the terminal attached to the carbon is 
known as the positive connection (commonly indicated by a plus 
sign +). It is to these terminals that the wires forming the external 
circuit of the cell are attached, the internal circuit being completed 
by the electrolyte and depolarizer. 

A single dry cell does not have enough power to produce a spark, 
so a number of these are generally joined to form a battery. The 
common method of connecting dry cells is in series; this means that 



Lubrication , Carburetion and Ignition 261 

the positive terminal of one cell is always coupled to the negative 
terminal of its neighbor. When cells are coupled in this manner, the 
battery has a voltage equal to that of one cell times the number of 
cells so joined. For instance, three dry cells would have a potential 
or current pressure of four and one-half volts, as one dry cell has a 
pressure of one and one-half volts. The amount of current produced 
by the batteries is measured in amperes and the battery capacity will 
depend upon the size of the active element and the strength of the 
electrolyte. The ordinary No. 6 dry cell which is six inches high by 
two and one-half inches in diameter will indicate a current strength 
of about twenty amperes. When cells are joined in series, the am¬ 
perage of the set is equal to that of but one cell. 

When dry batteries are used for motorcycle ignition purposes, they 
are always coupled together in a series connection to obtain the proper 
voltage and current strength. The dry battery has a number of ad¬ 
vantages, chief among which are its cheapness, ease of installation, 
compactness and simplicity. It has the disadvantage of being limited 
in capacity and not suited for continuous work, which it shares with 
all other forms of primary battery. When dry cells are exhausted, 
there is no method of renewing them to efficiency, and they must be 
replaced. They are seldom used on modern machines. 

The coming of electrical self-starting and lighting systems on motor¬ 
cycles has created some degree of interest in storage batteries, and in 
one machine, the Indian, which can be obtained with full electrical 
equipment, the battery current is employed for ignition purposes as 
well as for lighting and for starting the motor. 

The storage battery is a chemical current producer that is capable 
of being recharged when it is exhausted by passing a current of elec¬ 
tricity through it in a reverse direction to that of the current given 
out. Storage batteries are composed of elements of practically the 
same material, and can only become active when a current of elec¬ 
tricity is passed through them. The materials generally used are 
grids of lead filled with a paste composed of lead oxides. When the 
current of electricity passes through these plates, they become enough 
different in nature so that a difference of electrical condition exists 
between them, and when the cell is fully charged, a current may be 
drawn from it in just the same way as from a primary battery. 


262 Motorcycles , Side Cars and Cyclecars 

Storage batteries have the advantage that they may be used for 
continuous current production, and as they may be recharged when 
exhausted, it is not necessary to replace them with new members 
when they will no longer produce current. The storage battery is 
called a “secondary cell” because it can only give out energy after a 
current of electricity has passed through it, whereas a primary battery 
in good condition will produce electricity as soon as it is completed. 
The storage battery uses an electrolyte composed of dilute sulphuric 
acid and water, while a dry battery uses an alkaline electrolyte com¬ 
posed largely of sal-ammoniac. 

The average form of storage battery used for ignition, lighting or 
starting purposes is really composed of a number of separate cells, 
which are placed in a common carrying case of wood or hard rubber. 
The connection between the cells is made by plates of lead which are 
burned to the elements, leaving but two terminals free, one of which is 
a negative member while the other leads from the positive plates. 
To prevent spilling of the electrolyte, the top of the cell or battery 
is sealed with a hard rubber plate over which is poured a pitch and 
rosin compound. The electrolyte is renewed through a small vent in 
each cell which is covered by a removable hard rubber cap. These 
vents also allow for the escape of the gases evolved when the cell is 
being charged or when it is delivering a current of electricity. 

Parts of Simple Battery Systems. —The first system of ignition 
to be applied after the hot tube method had been abandoned was the 
various electrical systems in which batteries furnished the current. 
The wiring of two ignition systems for single-cylinder motorcycle 
engines is shown at Fig. 141, while a diagram showing the arrange¬ 
ment of parts and the method of joining them in a two-cylinder ig¬ 
nition system is outlined at Fig. 142. In the simple system depicted 
at A, Fig. 141, three dry cells are joined together in series to form a 
battery capable of delivering about 4.5 volts. This voltage would 
not be sufficient to leap the air gap or space between the points of the 
spark plug because it requires a pressure of several thousand volts to 
produce a spark between the plug points. Therefore, an important 
element of all battery systems is the transformer or induction coil 
employed to raise the voltage of the current so it will overcome the 
resistance offered by the air gap. It is not necessary to go deeply 


Lubrication , Carburction and Ignition 


263 


into the theory of induction coil action at this time because none of 
the present day motorcycles, with the exception of the Hendee Special 
Model Indian, utilize these members or batteries for ignition. In its 
simplest form, the induction coil consists of a core composed of soft 
iron wire around which is wound two or three layers of No. 16 or 18 
magnet wire. This is thoroughly insulated from another coil of very 
fine, thread-like wire comprising several thousand turns which is 
wound around the coil of coarse wire. The coarse wire is termed “the 
primary winding,” because the energizing current from the battery 
flows through it. The fine wire, which is not in electrical connection 
with the battery, but which is excited by induction, is termed “a , 
secondary coil” for this reason. In addition to the windings and 
core, a condenser is also included in the assembly which is contained 
in torpedo-shaped casings of hard rubber. Each time a current of 
electricity passes through the primary coil, an induced current of 
considerably higher voltage flows through the secondary coil. In 
order to insure that this rush of secondary current will only take 
place at such times that a spark is needed in the cylinder, a mechanic¬ 
ally-operated switch termed the “timer,” which is driven by the crank¬ 
shaft of the engine, is interposed in the circuit between the batteries 
and the primary coil. 

Considering first the four terminal coil shown at A, we find that two 
of the leads are insulated more heavily than the other two. The 
two wires with the thick insulation are secondary wires, and one is 
grounded while the other goes to the insulated terminal of the spark 
plug. The flow of secondary current is completed because the plug 
bodv, which carries one of the electrodes, is also grounded by being 
screwed into the cylinder casting. When a four-terminal coil is used, 
both terminals of the timer are insulated from each other, and the 
circuit is completed only when the platinum points on the timer spring 
and insulated contact screw are in contact. One of the primary wires, 
therefore, is attached directly to the insulated screw of the timer, 
while from the insulated contact spring another wire makes connection 
with the zinc terminal of the battery. The other primary terminal 
is connected to one side of a plug switch, while the wire from the 
carbon terminal of the battery is connected to the other. Before 
starting the engine, it is necessary to bridge the gap between the plug 


264 Motorcycles , Side Cars and Cyclecars 

switch members by a suitable metallic connector, and then, as the 
engine is rotated, the timer cam will bring the platinum points on 
the insulated spring and screw together, and close the primary circuit 
when the piston reaches the end of its compression stroke, and when 
the gas is fully compacted preparatory to explosion. Vibrator coils, 
which are very popular in automobile and marine service, are seldom 
used in motorcycle ignition systems, because with the high speed of 
the engine a single quick contact not only produces the required spark 
but means a considerable reduction in battery consumption. It is 
necessary to regulate the contact screw of the timer very carefully 
to secure the best results from the engine, and a difference of an 
eighth of a turn is often all that is needed to increase or reduce the 
engine speed appreciably. 

The wiring diagram presented at B is practically the same as that 
outlined above it, except that one of the secondary terminals is joined 
inside of the coil to one of the primary leads which goes to the 
battery. The primary wire P-1 goes to the insulated screw on the 
timer, and the primary wire P-2 goes to the carbon terminal of the 
dry cell battery. The zinc terminal of the battery is attached to one 
of the segments of the plug switch while the other member is grounded. 
The timer cam, which is attached to a metal shaft, is also grounded, 
and the current flow from the plug switch to the timer cam is through 
the metal parts of the engine and frame. But one secondary wire, S, 
projects from the coil, and this, of course, goes directly to the in¬ 
sulated terminal of the spark plug. 

When a two-cylinder engine is to be served by a battery ignition 
system, it is necessary to use two coils, one for each cylinder, and a 
two-point timer. The two induction coils are invariably housed in 
a single casing and are connected together inside in such a way that 
but five leads or wires extend from the coil case. Two of these are 
secondary wires, one from coil A and the other from coil B. The 
remaining two secondary leads are joined together inside of the coil 
casing and connected to the primary wire common to both coils. Two 
primary wires extend from the coil case that are electrically insulated 
from each other, as each of these serves an individual coil. The 
primary wire from coil A goes to the insulated contact at one side of 
the timer, while the primary wire from coil B is attached to the in- 


Lubrication , Carburetion and Ignition 


265 



Timer Cm 


- Ground 


Fig. 142.—Diagram of Battery Ignition System for Two Cylinder 

Engine. 


sulated contact at the other side. One end of the battery circuit is 
grounded as is also the timer cam. As the cam revolves, connection 
is made first between one pair of insulated contacts and then between 
the other. The spacing of the springs that are actuated by the cam 
is such that the explosions occur at the proper time in the cylinders 
and depend upon the method of placing the cylinders and design of 
the crankshaft. In the timer shown at Fig. 142, the explosions are 
separated by even intervals because the cam contact blocks on the 
timer springs are opposite each other and separated by a space equal 
to 180 degrees or half a revolution of the timer-cam travel 
















































































266 Motorcycles , Side Cars and Cyclecars 

A tinier used for single-cylinder engines is shown at Fig. 143 with 
all parts clearly indicated and one for two-cylinder power plants at 
Fig. 144. The basis of the tinier is often a block of fiber to which 
suitable binding posts are attached to support the vibrating spring 
and the contact screw. In the form outlined, these members are 
attached to terminals secured to the timer base by means of internal 
wires or suitable metallic connections. The wires comprising the 
outer circuit are attached to these terminals. The cam of the timer, 

shown at Fig. 143, is dif¬ 
ferent in form from that 
at Fig. 144. The former 
normally keeps the 
spring out of contact 
with the platinum-point¬ 
ed contact screw, and an 
electrical connection is 
established only when the 
cam rider or block on 
the end of the vibrator 
spring falls into the 
notch cut into the pe¬ 
riphery of the cam. In 
the form at Fig. 144, the 
cam has a raised portion 
which lifts the springs 

Fig. 143.—Timer Used in Connection With into engagement, and es- 
Battery Ignition System for One Cylin- u 

der Motor. y tablishes a connection 

by positive mechanical 
means instead of depending upon the spring tension as in the other 
construction. 

In order to produce a spark in the combustion chamber and yet 
have no leakage of gas, it is necessary to use a special fitting termed 
“the spark plug” between the points of which the ignition spark 
takes place. A typical spark plug is shown in section at Fig. 145. 
The central rod to which the terminal is attached passes through a 
porcelain body which insulates it from the steel portion that screws 
into the cylinder. Electrodes extend from the plug body to within 








Lubrication , Carburetion and Ignition 267 

a thirty-second of an inch of the central rod, and it is between these 
members that the spark takes place. Most of the motorcycle plugs 
are insulated with mica instead of porcelain, but the general principles 
of construction are the same in all. The only differences are in points 
of minor detail such as the size of the thread at the bottom of the 
plug body and the form of insulation and number of electrodes. 
Motorcycle spark plugs are provided in two thread sizes, the standard 
being the metric, which is considerably smaller and finer than the 
other, which is the regular half inch standard iron pipe thread. The 

spark plug is usually lo¬ 
cated in the combustion 
chamber in such a way 
that the points are in 
the path of the fresh 
gases as they enter 
through the open inlet 
valve as shown at Fig. 
146. Combination insu¬ 
lations, such as a mica 
corepressed in a porcelain 
shell, are used on some 
plugs, while others are 
lava or steatite for sep¬ 
arating the central elec¬ 
trode from the remainder 
of the assembly. 

High Tension Mag¬ 
neto Action. — Taking electricity from either a dry or storage 
battery is comparable to drawing a liquid from a reservoir filled 
with a certain definite supply. As the demands upon the res¬ 
ervoir increase, its capacity and the amount of liquid it con¬ 
tains become less in direct proportion. Batteries cannot maintain a 
constant output of electricity for an indefinite period, and their 
strength is reduced according to the amount of service they give. 
A mechanical generator of electricity produces current without any 
actual deterioration or depreciation of chemicals and plates, as is 
true of a battery. There is some wear present in a mechanical 



Fig. 144.—Form of Timing Device Employed 
in Battery Ignition System for Twin 
Cylinder Motor. 




268 Motorcycles , Side Cars and Cyclecars 

generator, but this is so small compared to the amount of service 
it will give that its effect is practically negligible as regards current 
output. 

A simple analogy that will enable one to appreciate the merits of 
the mechanical generator may be made with a pump system of draw¬ 
ing a liquid from a practically inexhaustible reservoir. As long as the 
pump is turned it will supply liquid. The same thing is true of a 
mechanical generator of electricity which will supply current as long 
as the rotating parts are turned. With batteries, when the engine 

speed increases, and the 
demands upon them be¬ 
come greater, the current 
strength decreases at a 
time it should be strong. 
With a mechanical gen¬ 
erator of electricity, the 
current output increases 
as the speed, and as 
these devices are usually 
driven directly from the 
engine, when this member 
demands more electricity 
the mechanical generator 
will supply it automat¬ 
ically because it is being 
driven faster. 

The high tension 
magneto is the form 
that is generally used in 
motorcycle ignition systems, and its popularity is increasing among 
other gas engine users as well. The main advantage of the true high- 
tension magneto is that it comprises in one device all the elements 
of the current generating and intensifying devices and all that is 
needed in connection with a high tension magneto are the spark plugs 
and the wires by which they are connected to the instrument. A high- 
tension magneto for a four-cylinder engine is but very little more 
complicated than one used on a two-cylinder power plant. The only 


FIBRE WASHER- 


PORCELAIN 


RUST PROOF 
STEEL BODY. 


LONG PORCELAIN 
8LEEVE 


HEAVY NICKEL 
POINT8 



SPRING WASHER 


8PRINQ TO ALLOW 
FOR EXPAN8ION AND 
CONTRACTION 


BRA88 8CREW 
GLAND 


ASBE8T03 

PACKING 


8TANDARD 

THREAD 


80LID NICKEL 
ROD 


Fig. 145.—Sectional View of Spark Plug 
With Porcelain Insulation. 






































Lubrication , Carburetion and Ignition 269 

difference is in the number of contacts in the distributor, and the 
speed at which the device is driven. 

A typical high-tension magneto utilized in connection with a single¬ 
cylinder engine is outlined in its simplest form at Fig. 147; and at 
Figs. 148 and 149, the parts and their proper relation are clearly 
shown. The armature is a two-pole type having an approximately 
H section, and it is wound with two coils of wire. One of these is a 



comparatively coarse one corresponding to the primary winding of 
an induction coil, while the other is a fine winding having many turns 
that performs the same function as the secondary coil. The armature 
shaft is mounted on ball bearings to insure easy rotation. The mag¬ 
netic field is produced by means of two horseshoe magnets attached 
to iron pole pieces which form the armature tunnel. Mounted on 













































270 Motorcycles , *SV<7<? Cars and Cyclecars 

and turning with the armature is a condenser which is placed in shunt 
connection with the contact points in the magneto breaker box. The 
armature is driven by positive chain or gear drive, and it is timed in 
such a way that the contact points of the magneto contact breaker 
separate only when a spark is desired in the engine. 

The contact breaker, which corresponds to the timer of a battery 
ignition system, consists of a fixed member which carries one of the 
platinum contact screws while the movable bell-crank lever carries 



Fig. 147.—Simplified Diagram Showing Arrangement of the Principal 
Components of True High Tension Magneto. 


the other platinum contact. The condenser is used to absorb a surplus 
current which is due to self induction between the various windings 
of wire and to prevent the excess current so generated from producing 
a spark that would tend to burn the contact points as they separate. 
The safety spark gap is interposed between the high-tension brush 
and the ground in such a way that any excess current that might 
injure the windings, if it was allowed to go through the instrument 
in the regular manner, will be allowed to flow to the ground without 






















Lubrication , Carburetion and Ignition 271 

passing through the external circuit. This device performs the same 
function for the magneto as a safety valve does for a steam boiler, in 
that it provides a means of escape for excess pressure that might 
injure the device if no means were provided for its disposal other than 
the regular channels of distribution. 

On a four-cylinder motor, the magneto is driven at crankshaft 
speed, the contact breaker cams being arranged in such a manner 
that the contact points separate twice during each revolution of the 
armature. Every time the contact points are separated a current 
of electricity leaves the armature by means of a high-tension brush 



Fig. 148.—Wiring Diagram Showing Method of Connecting Com¬ 
ponents of the Bosch Magneto. 


which bears on the insulated contact ring carried at one end of the 
armature shaft, and is led to a distributing brush at the center of the 
secondary current distributing member. The spark plugs are attached 
to wires which lead to the segments in the distributor, there being 
one segment for each spark plug. The distributor shaft is revolved 
at half armature speed by means of gears, and the revolving contact 
brush makes contact with one of the segments each time that the 
spark points separate, so the current of electricity is directed to the 
plug which is in the cylinder about to fire. It will be seen that this 
device includes the current generating and commutating means as 
well as the timing mechanism. 













































272 


Motorcycles , Side Cars and Cyclecars 


Operation of Standard High=Tension Magneto. —Some mag¬ 
netos intended for twin engines of the V-type have a special arrange¬ 
ment of the pole pieces, as indicated at Fig. 150, so the period of 
maximum current production will correspond to the point where ig¬ 
nition is desired. The armature of the magneto is driven at the same 
speed as the cam shaft, and the direction in which the armature is 
to rotate is indicated by the makers. The angle between the cylinders 


Longitudinal Section. 


Rear View 

(end cap removed). 




J. Brass plate. 

2. Slip ring. 

3. Carbon brush . 

4. Carbon holder. 

5. Interrupter dish. 

6. Interrupter lever. 

7. Spring. 


8. Contact piece. 

9. Screw. 

10. Timing arm. 

11. Steel segment. 

12. Binding post. 

13. Spring. 

14. Cover. 


15. Spring. 

16. Bolt for spring 15. 

17. Condenser. 

18. Dust cover. 

19. Short platinum screw. 

20. Long platinum screw. 

21. Conical fastening screw for 
carbon holder 4. 


Fig. 149.—Longitudinal Section and Rear View of Bosch Motorcycle 

Magneto. 

of the engine for which the magneto is intended is also indicated, and 
a magneto cannot be used for the reverse direction to that in which it 
is stamped or for an angle different from that indicated. As has been 
previously outlined in the operation of a twin-cylinder V-type four¬ 
cycle engine, each cylinder fires once during every two revolutions of 
the crankshaft, but the two firing strokes are not evenly spaced in 
the two revolutions, i. e., there is an interval of more than one revolu- 








































































Lubrication , Carburetion and Ignition 273 

tion between the firing strokes of cylinder 1 and cylinder 2, and an 
interval of less than a revolution between the firing stroke of cvlinder 
2 and the following firing stroke of cylinder 1. The revolutions of the 
crankshaft are therefore divided into a long period and a short period, 
and, as a rule, cylinder 1 is considered to be that which fires at the 
beginning of the long period, while No. 2 is that in which a spark 
takes place at the beginning of the short period. An examination 
of the interrupter or breaker box of such a magneto, which is clearly 
shown at Fig. 151, will show that the two segments are marked with 
the characters 1 and 2, and it will be observed that the dust cover of 
the magneto also bears these numerals which in that case refer to 
the two high-tension terminals which are also clearly shown at Fig. 
151. When the steel segment marked 1 is operating the interrupter, 
the carbon brush marked 1 will be in connection with the current- 
distributing segment on the slip ring, and the secondary current pro¬ 
duced at that instant will pass from the magneto to the spark plug 
connected to that brush. When the engine is installed in a motor¬ 
cycle, cylinder 1 is the member nearest to the rear wheel and is the 
one by which the magneto timer is set. The brushes are usually 
carried in easily removable members as at A, Fig. 152, which shows 
the brush for a one-cylinder magneto, or at B and C which show 
the exterior views and section of one of the brushes intended for a 
two-cylinder magneto. 

Magneto Driving Means. —As the magneto will produce current 
sufficient to overcome the resistance of the air gap at the spark plug 
only at a certain definite armature position, and as the contact- 
breaker points must separate coincidently with the attainment of 
the position of maximum current generation, it is imperative that the 
magneto be positively driven by the motor to which it is fitted, and 
by a method of drive that will obviate any possibility of slipping. In 
this respect, the magneto is different from a dynamo or, in fact, forms 
of magnetos which deliver a current of low voltage, and which require 
auxiliary timing and current intensifying appliances before the elec¬ 
trical energy is available for ignition. When the timing device forms 
part of the magneto, and is attached to the magneto armature, it is 
imperative that the contact-breaker points separate always at the 
same time in the cycle of operation. 


274 Motorcycles , Side Cars and Cyclecars 

A simple method of driving a magneto is shown at Fig. 153. In 
this, a chain extends from a sprocket on the cam-gear shaft to a 
member of the same size on the magneto armature shaft. The cover 
of the gear case and chain case is removed to show the relation of the 
parts to each other. As the chain is protected from abrasive material 
in the form of dust or grit, and as it is always thoroughly oiled, there 
will be but little wear or stretching. In this country, the general 
practice is to drive the magneto through a train of intermediate gears 
interposed between the cam-timing gears and a suitable member at¬ 
tached to the magneto armature. Some makers, notably Spacke and 
Pope, drive the magneto by means of worm or spiral gears, and, in 

some instances, this de¬ 
vice may be driven by 
beveled gearing. It is 
important to have the 
drive as direct as possi¬ 
ble, because in a system 
with a large number of 
gears there is apt to be 
some back lash develop 
between the various gear 
members after the engine 
has been used for a 
time, and this may interfere with the accuracy of the spark timing. 

Ignition Timing. —An important point in connection with suc¬ 
cessful operation of the magneto ignition system is that the break 
between the magneto contact points takes place just when it is 
desired to obtain a spark in the cylinder. Therefore, in timing a 
twin-cylinder motor, the engine should be turned over until the piston 
in cylinder 1 is at the top dead center or upper end of the compression 
stroke. The position of the piston may be determined by a wire 
passed through a pet cock or any other opening in the cylinder head, 
or by a suitable mark on the driving pulley provided by the maker of 
the engine to indicate that the piston has reached the top of its stroke. 
The magneto is then bolted to the base prepared for it with the 
driving gear loose on the armature shaft and the dust cover over the 
armature removed. The timing control lever attached to the contact 





Fig. 150.—Arrangement of Pole Pieces and 
Armature in Some Magnetos Intended 
for Two Cylinder V Engine. 













Lubrication , Carburetion and Ignition 


275 


breaker is placed in the full retard position which is done by moving 
it as far as it will go, in the same direction as the armature is driven. 
The armature should then be rotated by hand until the cam is sepa¬ 
rating the interrupter points. The armature should be held firmly in 
this position and the driving gear is then tightened on the armature 
shaft. It is imperative that there should be no slippage during this 
operation. Carbon brush 1 is connected to spark plug of cylinder 1 



11. Steel segment. 

12. Platinum point on inter¬ 
rupter lever. 

13. Platinum point on contact 
piece. 

14. Binding post. 



15. Short circuiting spring. 

16. Brass cover. 

17. Swinging spring. 

19. Dust cover. 

20. Condenser. 


Fig. 151.—Views Showing Contact Breaker and Distributor Arrange¬ 
ment of Bosch Magneto for Two Cylinder Engines. 


and carbon brush 2 to the spark plug in the remaining cylinder. Be¬ 
fore starting the engine to verify the timing, the dust cover should be 
replaced over the armature. Timing a single-cylindei engine is, of 
course, somewhat simpler as there is but one secondary lead from the 
magneto to the spark plug. 

The position of the piston in the cylinder of the Precision engines 
is shown at the top of Fig. 154, and it is at this point that the contact 





























276 Motorcycles , Ride Cars and Cyclecars 

points should be just separating, provided that the lever on the con¬ 
tact-breaker case is fully advanced. With the lever fully advanced, 
the spark points separate before the piston reaches the top of its com¬ 
pression stroke, whereas if the lever on the contact breaker is placed 
in the retard position the points should not separate until the piston 
has reached the top of its stroke. 



Fig. 152.—Carbon Brush Holders Used in Bosch Magneto, Showing 
Methods of Making Connections With Secondary Cable. 

If a two-cycle engine is to be timed, and the cranks are arranged 
at 180 degrees, as shown at Fig. 155, the explosions will be separated 
by equal intervals, and a form of magneto with regular type pole 
pieces may be employed. The contact breaker arrangement is such 
that the points are separated at equal intervals because there is no 
long period or short period as is the case with a Y-type, four-cycle 



































Lubrication , Carburetion and Ignition 


m 


engine. The arrangement of the pistons of a twin-cylinder four-cycle 
motor in which the explosions are evenly spaced is shown at the top 
of Fig. 156. A magneto of the same type would also be used with a 
double-cylinder opposed motor. In the V-type engine, shown at the 
bottom of Fig. 156, the explosion in cylinder 1 occurs at the beginning 



Fig. 153.—Depicting Application of Roller Chain to Magneto Drive. 

of the"period that is equal to one complete revolution plus the angle 
A between the cylinder center lines while the explosion in cylinder 2 
occurs one revolution minus the angle between the cylinders after 
the explosion in cylinder 1. 








278 


Motorcycles , Side Cars and Cyclecars 


The arrangement of the contact breaker and distributor parts of a 
four-cylinder magneto is shown at Fig. 157. Just as the cam R is 
about to separate the contact points, the metal distributing segment 
of the distributor should be in communication with one of the in¬ 
sulated brushes that are connected to the plugs in the various 
cylinders; in this case, it would complete the circuit between the 














































Lubrication , Carburetion and Ignition 


279 


central distributing member and the brush connected to the cylinder 
about to fire. 

In order to cut off the ignition, the primary circuit of the magneto 
must be grounded, and this may be accomplished by either of two 
methods. The one most commonly used in this country is retarding 
the ignition to an extreme point, at which position of the interrupter 
housing, a flat spring attached to the primary binding post is brought 
in contact with a grounded pin located on the magneto end plate. 
Another method is to connect the binding post to the ground through 





Fig. 155.—Arrangement of Cranks in Two Cylinder Two-cycle Engine 

to Secure Even Firing Intervals. 

the medium of some form of switch, one wire being connected to the 
binding post and the other switch wire being led to any convenient 
part of the engine or frame. A cut-out switch adapted for location 
on the handle bars of a motorcycle is shown at Fig. 158. A block of 
fiber serves to insulate the contact spring from the handle bar, and 
when it is desired to ground the circuit, a contact is established 
between the end of the spring and the handle bar by pressing on the 
hard rubber knob at the free end of the spring. The action of a 


































































280 


Motorcycles, Side Cars and Cyclecars 



Fig. 156.—At Top, Arrangement of Crank Pins in Two Cylinder Ver¬ 
tical Engine to Secure Even Periods of Time Between Explosions. 
Below, Usual Arrangement of Crankpin in Two Cylinder Motor¬ 
cycle Powerplant. 





























































































Lubrication , Carburetion and Ignition 281 

magneto switch is radically different from that of the type employed 
for battery ignition. With the latter, the current will not flow unless 
the primary circuit is completed, whereas with a magneto, completing 
the primary circuit means a discontinuation of current generation. 
What would be the “on” position in a battery switch is the “off” 
position in a magneto system. 



Fig. 157.—Contact Breaker and Distributor of Four Cylinder Magneto. 


Detection of Faults. —The following instructions are issued by 
the makers of the Bosch magneto, and as they cover the ground 
thoroughly, they are reprinted verbatim: 

In case of a fault in the ignition system, the firing will become 
irregular or will cease entirely. In case of irregular firing, the fault 
is almost invariably due to a defective spark plug, and if this con¬ 
dition is noticed the spark plugs should be changed. 


























Motorcycles , Side Cars and Cyclecars 


282 


To locate the cylinder that is misfiring, disconnect the cable from 
spark plug 1 and crank the engine. If the engine operates on cylinder 
2 under these conditions, it shows that the ignition of that cylinder is 
correct and locates the defect in cylinder 1. However, should no 
ignition occur, the spark plug of cylinder 2 is defective and must 
therefore be replaced. 

The more common defects of spark plugs are as follows: 

First.—Fouling of the plugs, due to the carbonization of the in¬ 
sulation. A fouled plug may be cleaned by the use of a stiff bristle 
brush dipped in gasoline. 

Second.—Too large a gap between the electrodes of the spark plug. 
The normal spark plug gap should be from 0.5 to 0.6 millimeter 
(about 1 /64 inch), smaller or larger gaps being detrimental to good 
ignition. If the gap between the spark plug electrodes is too great, 
the current will discharge across the safety spark gap on the magneto. 
When the plug is unscrewed from the cylinder, however, the spark 
will jump across the plug electrodes instead of across the safety spark 
gap. This does not signify that the distance between the spark plug 
electrodes is correct, for when the spark plug gap is subjected to the 
compression that exists in the cylinder the resistance between the 
points of the gap is greatly increased. 

The distance between the spark plug electrodes must therefore be 
much less than is required when the spark passes in the open air. 

Third.—Short circuiting of the spark plug by metallic beads formed 
across the spark plug gap by the intense heat of the magneto current. 
The removal of these metallic beads will correct the difficulty^. 

If ignition fails suddenly, there will probably be a short circuit in 
the cable connected to binding post 170 and leading to the switch. 
A difficulty of this sort may be determined by disconnecting the cable 
from the magneto and testing to see whether ignition is resumed. 
Should ignition still prove faulty and irregular, the interrupter should 
be inspected to ascertain if the interrupter lever moves freely, and if 
the platinum points make good contact. 

Should ignition be irregular in both cylinders, the contact points 
should be examined, which may be done by swinging spring 17 to 
one side and removing cover 16 (Fig. 151). 

The following points should be observed: Screw 9 should be screwed 


Lubrication , Carburetion and Ignition 


283 


tight into position; the platinum-pointed screws 12 and 13 should 
make contact when the interrupter lever 6 is not touching the steel 
segments 11; the distance between the platinum-pointed screws should 
be about 0.5 millimeter when the interrupter lever 6 is resting on one 
of the steel segments 11, and the metal blade, pivoted to the adjusting 
wrench that is supplied, may be used as a gauge for this distance. 

If the parts of the interrupter appear to be in order, screw 9 may 
be withdrawn and the contact-breaker disk removed complete. The 
platinum points should be examined, and if they are rough or worn— 
but only in this event—they should be trued with a fine flat file, or 



Fig. 158.—Magneto Cutout Switch for Attaching to Motorcycle 

Handlebars. 


with fine emery cloth. If they are oily and dirty, they should be 
cleansed with gasoline. The surface between spring 15 and the screw 9 
should be kept clean. 

An investigation as to the cause of trouble may be summarized as 
follows: First, change the spark plug; second, examine the spark 
plug cable; third, test for trouble in the switch or switch cable by 
operating the magneto with the cable disconnected from binding post 
170; fourth, examine the interrupter lever for free movement; fifth, 
dismount the interrupter to examine platinum contacts. 

The armature is supported on ball bearings and should be lubricated 
with a few drops of light oil every 300 to 500 miles, applied to the 












284 


Motorcycles , Side Cars and Cyclecars 


oil holes, which can be found at each end of the magneto, covered 
by hinged brass plates. 

The other parts of the apparatus require no lubrication, and care 
should be taken to prevent the introduction of oil into the interrupter 
parts. These operate without lubrication, and oil will interfere with 
their action. 


CHAPTER V. 


POWER TRANSMISSION SYSTEM PARTS. 


Utility of Clutch Defined—Theory of Friction Clutch Action—Types of 
Clutches—Materials Employed in Clutches—Clutch Location—Typical 
Motorcycle Clutches—Why Change Speed Gearing is Desirable—Value 
of Variable Speed Gearing—Variable Speeds by Slipping Clutch—Change 
Speed Gear Location—Variable Speed Pulleys—Engine Shaft Gear— 
Countershaft Gears—Rear Hub Gears—Three Chain Systems—Planet¬ 
ary Countershaft Gears—Sliding Gear Type—Power Transmission 
Methods—Belt Drive Systems—Types of Belts—Standard Belts—Ad¬ 
vantages of Drive by Chains—Single Chain Direct Drive—Double 
Chain Drive—Types of Driving Chains—Combination Chain and Belt 
Drive—Bevel and Worm Gear Final Drive—Relation of Engine Power 
to Gear Ratio. 

The power transmission group is next in importance to the energy 
producing elements and much depends upon correct application of 
the various devices utilized in transmitting the engine energy to the 
traction member. The efficiency of the motorcycle as a whole de¬ 
pends largely on that of the power transmission system. An ex¬ 
tremely powerful and effective motor is of little avail if a large pro¬ 
portion of the power it produces is consumed by friction or trans¬ 
mission losses before it can be applied to the rear wheel to produce 
useful work. The principal elements of the transmission system of a 
simple motorcycle are first, a clutching device that permits of releasing 
the engine from the driving medium or applying the power at will, 
and second, some system of transmitting the engine power from the 
clutch to the rear wheels. Many of the 1914 motorcycles include 
still another element, the variable speed gear, in the power trans¬ 
mission system. 

Utility of Clutch Defined. —Practically every motorcycle pro¬ 
duced at the present time is fitted with a free engine and clutching 
device that will permit of running the engine without driving the 
vehicle. In the early days of motorcycle development, the drive was 

285 



28G 


Motorcycles , Cars and Cyclecars 


direct from the engine crankshaft to the rear wheels without any 
engine releasing device. It was necessary to start all motorc 3 ^cles by 
a preliminary pedaling process which meant that the entire machine 
had to be pushed along briskly regardless of character of road surface 
or gradients so the motor would be turned sufficiently fast to start. 
It was not possible to put the machine on a stand, as is done at the 
present time, because the absence of the free engine device made it 
imperative that the machine should acquire a certain amount of 
momentum before the power was applied. The result was that it 
required a very strong person to start a powerful twin-cylinder motor 
fitted to a heavy machine, because, while the machine might start in 
ten feet, it might require vigorous pedaling for half a city block 
before the engine was started. When the engine did start, it was apt 
to race or take hold suddenly because very often the spark would be 
well advanced or the throttle would be opened to secure easy starting. 
The sudden application of power was not favorable to the power 
transmission system and snapped chains or broken belts were not an 
uncommon result when the power was suddenly applied in this 
manner. 

When a free engine clutch is employed, it is possible to place the 
machine on a stand and start the power plant with comparative ease 
because the only resistance to overcome is that offered by the motor 
itself instead of the rider having to furnish the power to move the 
heavy machine along the road. After the engine is started, it is 
possible to release the clutch and disconnect the power from the rear 
wheels. This enables the rider to take the machine off the stand, 
keep the engine running, and start off very gradually by utilizing the 
power of the motor which is delivered to the rear wheel in gradually 
increasing increments if the friction clutch is let in slowly. Another 
advantage of the clutch is that it permits of ready control under 
unfavorable riding conditions such as in traffic, climbing hills, or over¬ 
coming poor highway surfaces. Instead of controlling the machine 
by continually interrupting the motor action, as was the case in the 
old direct drive days, a twist of the grip on the handle bar or an easy 
movement of a conveniently placed lever will release the clutch, inter¬ 
rupt the drive and permit the rider to bring his machine to a stand¬ 
still, if necessary, without stopping the motor. 


Power Transmission System Parts 


287 


The control of modern machines is very similar to that of an auto¬ 
mobile, and is such an improvement over the old system that its 
importance is not apt to be realized except by those of us whose 
experience dates back far enough so we can qualify as veteran motor¬ 
cyclists. With the old forms of machines, when a patch of sand was 
encountered or a gradient that did not permit one to “rush” the hill 
by putting on full speed before reaching the bottom and depend 
largely on momentum to assist in overcoming the resistance, it was 
necessary to either get off and push the machine or to endeavor to 
assist the engine by vigorous pedaling. If perchance one was un¬ 
fortunate enough to become stalled in the middle of a hill, it was 
practically impossible to make a new start without returning to the 
bottom and making another rush to overcome the unfavorable con¬ 
ditions. At the present time, if an engine tends to slow down, due 
to a patch of sand or other resistance, the rider can slip the clutch 
a trifle, enable the engine to pick up speed so that it will not stall, 
and yet deliver enough power to the rear wheel to obtain positive 
drive. 

Theory of Friction Clutch Action. —Clutch forms that are ap¬ 
plied to motorcycles are invariably of the friction type, as no progress 
has been made in utilizing the various hydraulic, pneumatic, or mag¬ 
netic clutches that have been offered at various times by over-sanguine 
inventors. The friction clutch has proven to be the most satisfactory, 
and has received wide practical application in its various forms. The 
important requirement of a clutch is that it will be capable of trans¬ 
mitting the maximum power of the motor without any loss due to 
slipping when fully engaged. A clutch should be operated easily and 
require but minimum exertion on the part of the operator. A clutch 
should be gradual in action, i. e., when it takes hold, the engine power 
should be transmitted to the driving member in a gradual and uni¬ 
form manner or the resulting shock may result in serious injury to 
some part of the driving mechanism. It is also imperative that a 
clutch release at once when desired, and that there be no continued 
rotation of parts, which insures that the drive will be interrupted 
positively when the clutch is disengaged. In considering the design 
of a clutch, it is very desirable that this component be located in an 
accessible manner, which is a good feature, as it permits of easier 


288 


Motorcycles , Side Cars and Cycle cars 


removal for inspection, cleaning and repair. It is imperative that 
some form of adjustment be provided so a certain amount of wear 
will be compensated for, without replacing any expensive parts. A 
simple design with a minimum number of operating parts is more to 
be desired than a more complicated form which may have some minor 
advantages, but which is much more likely to cause trouble. 

To illustrate the transmission of power by frictional adhesion of 
various substances with each other, one can assume a simple clutch 
form consisting of two metal discs or plates in contact, the pressure 
keeping them together being due to the weight of one member bearing 
upon the other. If the discs are not heavy, it will be found easy to 
turn one upon the other, but if weights are added to the upper member 
a more decided resistance will be felt which will increase directly as 
the weight on the top disc and consequently the total pressure aug¬ 
ments. It is possible to add enough weight so it will be difficult to 
move one plate without producing a corresponding movement of the 
other. If one of these plates is mounted on an engine shaft, and the 
other applied to the transmission member so that a certain amount of 
axial movement is possible, and the pressure maintaining contact was 
obtained by springs instead of weights, one would secure a combina¬ 
tion capable of transmitting power, inasmuch as the spring pressure 
applied to one disc would force it against the other, and one shaft 
could not revolve without producing motion of the other. 

Types of Clutches. —Three main forms of friction clutches have 
been employed in motorcycles, and these, in the order of their im¬ 
portance, are disc, plate, band and cone designs. The disc clutch is 
the most popular because it is a compact form, and in its simplest 
design it would consist of a casing driven by the engine with a series 
of discs attached to it, and another member carrying another set of 
discs that was connected to the driving wheel by suitable gearing. 
The discs attached to the case are distinct from those carried by the 
driven member, and driving contact is maintained between the twoby 
steel springs. It is possible to house a multiple disc clutch in an oil- 
tight casing, which means that it is possible to slip this form of clutch 
much more than the cone or band types, which for the most part 
operate without lubricant. A large number of small diameter discs 
are employed to transmit the power, and the required contact area 


Power Transmission System Parts 


m 


Clutch Case, 


ressore 

P\ate 


rochet 



Driving 

Member 


An chord 


Spr\no Pressure 

Adjustment 


Fig. 159.—Sectional View of the Eclipse Engine Shaft Multiple Disc 

Clutch. 

is obtained by the use of a number of comparatively small surfaces, 
instead of two larger ones, as is the case with the cone or band clutch. 




























































































Motorcycles , Side (dvrs and Cyclecars 


290 

The type of multiple disc clutch that is the most widely adopted 
is shown at Fig. 159, and, while the form outlined uses discs of the 
same material, in some forms of clutches one set of discs will be of 
steel while the other will be of phosphor bronze. The drive from the 
engine shaft is taken by a driving member keyed to it, and one set 
of plates is securely fastened to this member. The remaining plates 
are attached to the clutch case and revolve with it and the drive 
sprocket that goes to the rear wheel is also secured to the clutch case. 
The pressure to maintain the plates in frictional contact is obtained 
from a series of coil springs which act against a pressure plate which, 
in turn, bears against the disc assembly. The use of oil in this form 
of clutch is of advantage because it not only promotes easy engage¬ 
ment by interposing an elastic cushion between the metal plates and 
thus prevents too rapid engagement, but it also reduces depreciation 
when the clutch is released or the discs are slipping by each other 
because of its value as a lubricant. Owing to the small diameter of 
multiple disc clutches, the inertia of the driven member or tendency 
to rotate when disengaged is less than in a cone clutch or band form 
of larger diameter. The spring pressure is usually sufficient to squeeze 
the oil from between the plates as soon as the clutch is fully engaged, 
and a metal to metal contact is then obtained. In fact, if the lubricant 
was retained between the surfaces, the cjutch would slip, but as it is 
gradually forced out and there is a certain amount of slipping as long 
as any of the lubricant remains, this feature insures that the power 
will be applied in a gradual manner even if the clutch is carelessly 
operated. 

The cone clutch in its simplest form consists of a female member 
in the form of a saucer-shaped metal piece, and a male member, which 
is a truncated cone, which fits into it, and a spring or leverage to 
maintain frictional contact between the surfaces. The male member 
is usually faced with some frictional material to secure better driving 
power through superior frictional adhesion. Band clutches may be 
of two forms. The one that is most generally used in connection 
with planetary speed change gearing consists of a steel band lined 
with frictional material that contracts against a drum or an internal 
band which is expanded inside of the drum. The internal form is 
generally used when it is desired to keep both parts in motion, as 


Power Transmission System Parts £91 

for instance in transmitting power between the shaft on which the 
expanding band is attached to the drum against the inside periphery 
of which it bears. The constricting band clutches are generally used 
in the form of a brake to restrain the motion of a planetary gear 
carrying member in order that the gears will transmit power. 

Materials Employed in Clutches. —One of the important points 
in clutch design is to secure as much frictional adhesion between the 
parts as possible. The transmitting efficiency of a clutch will vary 
with the coefficient of friction (which means the amount of adhesion) 
under pressure and, of course, the more friction between the surfaces 
for a given amount of spring pressure the more suitable the clutch 
will be for transmitting power. A metal usually forms one frictional 
surface in all forms of clutches, and some types, notably the multiple- 
disc forms, have all friction surfaces of metal. The metallic materials 
generally used are cast iron, aluminum and bronze castings, and sheet 
steel and bronze in the form of thin stamped discs. The non-metallic 
frictional materials often employed are leather, asbestos fabrics, tex¬ 
tile belting and cork. Leather is the best lining or facing for clutches 
where the friction area is large and where the clutch is not apt to be 
slipped much. When used, it must be kept properly lubricated and 
soft because, if it becomes dry, it will engage very suddenly and 
promote harsh clutch action. Care must be taken not to supply too 
much oil, because the co-efficient of friction will be reduced to a low 
point and the surfaces will slip by each other. Chrome-tanned 
leather is generally used because it has good wearing qualities and, 
in addition to being a very resilient material, it possesses a very satis¬ 
factory degree of frictional adhesion when pressed against a cast iron 
member. Oak-tanned leather is also used for clutch facings. A 
clutch for motorcycle use should be faced with asbestos fabric rather 
than leather, unless it formed a part of a two-speed gear, which 
would not require slipping the clutch to any extent. These asbestos 
fabrics, of which raybestos is one of the best known, are used to some 
extent as a facing in multiple disc clutches of the dry plate type. 
Cork is sometimes used in connection with metal surfaces in the form 
of inserts which are compressed into suitable holes machined to receive 
them. Cork has a high coefficient of friction, and is not materially 
affected either by excessive lubrication or lack of oil. The cork inserts 


292 


Motorcycles , Side Cars and Cyclecars 


promote gradual engagement and possess very desirable wearing 
qualities. Metal to metal surfaces are the rule in multiple disc or 
plate clutches of small diameter where a multiplicity of surfaces are 
depended on for driving, but when a lesser number of plates of larger 
diameter are used, cork inserts or an asbestos fabric ‘facing are in¬ 
variably provided on one set of plates. 

Clutch Location. —There are three points in a motorcycle where 
it is possible to apply a friction clutch, these being on the engine 
crankshaft, on a countershaft, or in the rear wheel. The faster the 
parts of a clutch turn, the smaller in diameter they can be to transmit 
the same amount of power, and for this reason the engine shaft is 
favored by a number of makers. Sometimes the clutch is attached 
directly to the crankshaft extension, to which the sprocket would 
normally be fastened in a direct or countershaft drive con¬ 
struction, and at the present time the engine shaft location is growing 
in favor. The most general location, which may be considered typical 
of standard practice, is at the crank hanger, which involves the use 
of a larger clutch on account of the lessened speed of that member. 
If the clutch is housed in the rear hub it must be even larger, i. e., it 
must have a greater number of discs if it uses the same spring pressure 
as either an engine shaft or countershaft clutch or it must employ 
higher spring pressure if it uses the same number of discs as would 
ordinarily be used in either of the other locations. It is contended 
by those who favor the rear wheel location, that while the clutch 
parts must be larger, they are also more substantial and stronger, and 
owing to the reduction in speed the surfaces are not apt to wear as 
rapidly when they slip by each other with the clutch partially released 
as would be the case in an engine-shaft clutch or even the countershaft 
type. The latter form is a compromise between the two extremes, 
the engine-shaft clutch on one hand and rear hub form on the other. 

Typical Motorcycle Clutches. —The multiple disc clutch shown 
at Fig. 159 is the engine-shaft type, and is very compact as well as 
effective. When the springs are compressed to release the clutch by 
drawing the pressure plate away from the disc assembly; the outer 
casing which carries the driving sprocket revolves on a double row 
ball bearing, the inner race of which is formed by the driving member 
attached to the engine shaft. To release the clutch, a suitable lever, 


Power Transmission System Parts 


293 


provided with an internal spiral thread, is rocked on a fixed member 
which has an external spiral thread. This fixed member communicates 
with the pressure plate through the medium of a ball thrust bearing, 
and as the clutch release lever is moved, the spiral thread or worm 
produces a lateral displacement of the pressure plate. 

Another form of engine-shaft clutch is shown at Fig. 160. In this, 



Fig. 160.—Sectional View of the Pierce Cone Actuated Multiple Disc 

Clutch. 


the clutch is applied by a series of bell cranks which are provided at 
one end with an adjustable pressure screw bearing against the pressure 
plate of the disc assembly, and a bearing portion at the other end 
which works against a movable cone member that applies the clutch 
by spreading out the bell cranks and squeezing the driven and driving 
disc assemblies together. 

The Eclipse countershaft clutch shown at Fig. 161 has been 'widely 
specified, and is the same in general construction and principle of 
operation as the form shown at Fig. 159, except that the drive from 









































































294 Motorcycles , Side Cars and Cyclecars 

the engine goes to a sprocket attached to the clutch casing while the 
driving sprocket is secured to the inner member, which in this case 
is the driven instead of the driving portion of the clutch. The re¬ 
leasing means is similar to that previously described and is by spirally 
threaded members. 

The countershaft clutch shown at Fig. 162 is used on Indian motor¬ 
cycles, and while it is a multiple disc form it employs friction facing 



Fig. 161.—Sectional View of the Eclipse Countershaft Type Free 

Engine Clutch, 
















































































Power Transmission System Parts 


295 


Fig. 162 .—Countershaft Type Multiple Disc Clutch Used on Indian 

Motorcycles. 

on part of the discs instead of utilizing the metal-to-metal contact. 
This view is valuable also, in showing the method of application of a 
countershaft clutch assembly in a carrier member adapted to fit the 
crank hanger box of the frame. The method of releasing this clutch 
is similar to that employed in the other forms as it involves a movable 
worm operating in a fixed, internally threaded member. The angle 
of the threads on the worm is such that as it is rocked in the nut it 


Sprocket Driven By Eno'me 


Cavntv 





























296 


Motorcycles , Side Cars and Cyclecars 


advances and pushes against a rod passing through the center of the 
countershaft and securely attached to the pressure plate which forms 
the outer member of the clutch case. The pressure plate is normally 
kept in contact with the clutch disc assembly by small coil springs 

which exert their pressure 
against cups carried by 
the pressure plate. The 
springs are compressed 
to a suitable degree by 
adjustable nuts carried 
on bolts that hold the 
inner and outer clutch 
members together and 
which tend to clamp the 
disc assembly between 
them. The large sprocket 
is driven by the engine, 
while the small one is 
employed to drive the 
rear wheel. 

The cone clutch used 
on the Reading-Standard 
motorcycle is outlined at 
Fig. 163. As all import¬ 
ant parts are clearly de¬ 
picted, the reader should 
have no difficulty in fol¬ 
lowing the method of 
operation. In this clutch 
the spring is a releasing 
member and not an actu¬ 
ating member, as is true 
of the forms previously 
described. The clutch assembly is mounted on a spindle which is 
securely attached to a plate or anchorage member fastened to the 
engine base. The drive from the crankshaft to the male clutch 
member is through a spur pinion attached to the crankshaft which 



Fig. 163.—Sectional View of the Reading- 
Standard Cone Clutch. 
























































































































Power Transmission System Parts 


297 


meshes with a larger internal gear member that drives the male 
clutch casting. The female clutch member carries the drive sprocket 
that is connected to the rear wheel by a suitable chain, and in some 
models it drives a V-belt pulley. 

Contrary to the usual cone clutch practice, the male clutch member 
does not move axially because it is held positively in place on the 
clutch spindle by two cup and cone bearings that prevent any end¬ 
wise movement. To apply the clutch, the female clutch member is 
moved axially by a face cam arrangement. The oscillating face cam 
member, which has a series of inclined planes on its surface, is attached 
to a shaft that is moved by the clutch applying lever. A sliding face 
cam member that cannot rotate because it fits a squared portion of 
the clutch spindle is moved against the ball thrust bearing and presses 
the female clutch member firmly against the male clutch member as 
the pressure-applying lever oscillates the movable face cam member. 
When the clutch-applying lever is moved in a direction opposite to 
that necessary to apply the clutch, the face cam members separate 
and the clutch release spring pushes the female clutch member, which 
is movable, away from the male clutch member that is mounted on 
bearings that permit only a rotary movement. It is advanced by 
those who favor this form of clutch construction that much more 
gradual application is possible as the pressure is at the control of the 
rider than if obtained by means of the usual spring. It is claimed 
that should conditions demand it sufficient pressure may be exerted 
to lock the two portions of the clutch together into practically a single 
unit, whereas springs sometimes become weakened, and as the driving 
pressure is not positively maintained there is no way of remedying 
the slipping due to weakened springs except by replacing them or 
making a suitable adjustment of the pressure plate so the springs are 
compressed more tightly. The male clutch member is faced with 
frictional material in order to secure greater adhesion between the 
driven and driving members. 

An example of a free engine clutch of the multiple disc type in¬ 
stalled in the rear hub is shown at Fig. 164. This hub is used on Rex 
motorcycles which are of English manufacture. The driving member 
forms an inner hub that is independent of the outer hub shell except 
for the driving connection that exists when the discs are pressed 



298 


Motorcycles , Side Cars and Cyclec airs 


together. The flanged driving member B is attached to' the driving 
pulley by suitable spokes and revolves on ball bearings P. The outer 
hub shell, which carries one set of discs is mounted on bearings N. 
When the clutch assembty K is pressed together by the springs J, 
the main hub A and the driving member B are securely locked together 
and ball bearings N do not revolve. When the internally threaded 
member E is moved on the externally threaded member or worm F, 



it exerts pressure against the transfer rod G passing through one end 
of the axle R and pushes against a ball thrust bearing H which com¬ 
presses the springs J by moving the pressure plate away from the 
disc assembly. When the discs are free, outer hub A can turn on ball 
bearings N independently of the member B, which continues to 
revolve as long as the engine is in motion. 














































































































Power Transmission System Parts 


299 


Why Change Speed Gearing Is Desirable— While the intro¬ 
duction of the friction clutch was a great step in advance, and made 
for rapid development of the motorcycle industry because it made it 
possible for people to operate motorcycles who would find it extremely 
difficult to manipulate the old directly connected types, still there is 
something lacking in a machine that is equipped only with a free 
engine clutch. We have previously considered the effect of the vary¬ 
ing conditions upon the power needed to propel a motorcycle, and 
the writer has endeavored to make clear the relation the gear ratio 
must bear to the resistance. Under favorable conditions of operation, 



Fig. 165.—Indian Motorcycle With Two Speed Countershaft Gear. 


when there is no undue influence to retard the progress of the machine, 
it is possible to drive the motorcycle without the expenditure of the 
entire energy the power plant is capable of. This makes high speeds 
possible and enables the engine to turn over at a number of revolu¬ 
tions that will permit it to exert the power necessary or even an actual 
surplus of energy. In a direct connected machine, as the resistance 
to motion increases, the tendency of the power plant is to slow down, 
which means that the power output is diminishing at a time that 
more is needed. If, therefore, some form of auxiliary gearing is pro¬ 
vided that will permit the engine to run at its maximum speed and 
yet reduce the rear wheel and vehicle speed proportionate to the 













soo 


Motorcycles , Side Cars and Cyclecars 


resistance encountered, it will be possible for the engine to exert its 
full power at those times when the full capacity is needed, and, what 
is more important, the interposition of positive reduction gearing 
means that the power will be transmitted to the traction member 
where it can do useful work instead of being dissipated by heating 
the friction members of a slipping clutch. 

Value of Variable Speed Gears. —If a two-speed or other variable 
gear did not permit of any other advantages besides enabling one to 
surmount gradients steeper than could be taken with a single-geared 
machine, this alone would justify its existence and make it profitable 
to install them in the modern motorcycles. When one considers that 
they permit of easy starting under any road condition or on any 
grade, and that they also make possible increased safety and superior 
control of the motorcycle in traffic, it will be understood why the 
general demand of the discriminating rider is for two-speed gears or 
equivalent devices. 

A two-speed gear makes it possible to provide a smaller power 
plant without reducing the actual ability of the motorcycle in the 
least. It will climb any grade a single-geared motorcycle of greater 
capacity would surmount, and would be able to overcome many 
gradients and unfavorable road surfaces that the larger and more 
powerful machine could not be operated on. It provides positive 
control in traffic, a smooth running, and lack of vibration under all 
conditions that obviously could not be obtained with an engine having 
a larger piston displacement and proportionately greater force to the 
explosions. The small engine will also provide a satisfactory speed 
on the level, because on the direct drive or high gear the ratio may be 
sufficiently high to permit of high speed, owing to the provision of 
the reduction gearing to permit use of the lower ratio at such times 
as the resistance becomes too great to be overcome by the direct 
drive. The reduction of power plant capacity made possible by the 
two-speed gear will promote several other improvements in motor¬ 
cycle design that will appeal to many of conservative temperament. 
The most important of these is undoubtedly the reduced cost, both in 
initial expense and maintenance of the lighter machine. If the power 
plant capacity can be reduced, then the weight of the motorcycle 
may be lessened, owing to the materially diminished stresses on the 


Power Transmission System Parts 


301 


frame, power transmission and supporting members. It costs less to 
drive a lighter machine, there is less depreciation and wear and tear 
if vibration is reduced. Smaller tires, less gasoline and oil consump¬ 
tion, greater comfort, and improved control are all desirable factors 
that will increase the pleasure of motorcycling, and augment 
the ranks of motorcyclists, and thus directly benefit the entire 
industry. 

Variable Speed by Slipping Clutch. —Many motorcyclists are 
under the impression that the friction clutch in its various forms will 
permit of sufficient variation in the gear ratio to provide a margin of 
reserve power for hill climbing not obtained with a rigid drive 
machine. The free engine clutch is a very desirable improvement in 
motorcycles and has many advantages, inasmuch as it will permit 
the motorcycle to be started from a standstill, and enables the rider 
to stop his machine in traffic without stopping the power plant. It 
also provides for superior control in traffic, but is not an effective 
substitute for a variable speed gear of the positive type. 

As any reduction in rear wheel speed, relative to that of the power 
plant, can only be obtained by slipping the clutch, it is obvious that 
the power lost in slippage between the friction surfaces can serve no 
useful purpose at the contact point of rear wheel and ground, and, in 
fact, if enough power is allowed to waste in this manner, sufficient 
heat may be generated by friction to seriously injure the mechanism 
comprising the clutch. As it is the rear wheel horse-power that counts 
in climbing hills or in pulling through sand, the variation in ratio 
between the engine shaft revolutions and rear wheel speed obtained 
by slipping the clutch does not increase the torque or pull at the rear 
wheel to any extent, and therefore is ineffective. 

Consider a case where we have a motor capable of delivering 12 
horse-power at 2,500 revolutions per minute. Almost any of our 
modern twin engines with a nominal rating of 8 to 10 horse-power 
can produce this energy. Assume that our gear ratio is 4 to 1, this 
means that with the clutch locked in positive engagement, that the 
rear wheel will be driven at 625 revolutions per minute, and that the 
rear wheel pull or effective power is equal to the capacity of the power 
plant minus the loss in transmission. If we assume 20 per cent, loss 
in transmission, we have an effective torque such as produced by 9.5 


302 Motorcycles , Side Cars and Cyclecars 

| 

horse-power, and our rear wheel is revolving at 625 revolutions per 
minute. 

Suppose we have a two-speed gear that will reduce the rear wheel 
speed to half that obtaining on the high or direct drive. If our engine 
runs at 2,500 revolutions per minute and our rear wheel turns at 312.5 
revolutions per minute, we have practically the same effective torque 
as at the higher rear wheel speed, which obviously could not be used 
in climbing gradients because the increased resistance and the de¬ 
crease in vehicle speed must be proportionate, if only the same amount 
of power is available at the motor. Of course, there would be a 
further loss due to the gearing, which would be compensated for by 
the lessened wind resistance due to the lower motorcycle speed. It 
will be evident that the introduction of a speed-reducing gear cannot 
increase the effective horse-power of the motor except that it permits 
the power plant to attain the same speed as with the higher ratio, 
whereas the motorcycle speed is reduced because the ratio of drive 
between rear wheel and engine is now actually 1 to 8. 

Consider the result obtained by a slipping clutch in comparison 
with that secured by the interposition of intermediate speed-reduction 
gearing. The resistance to motion is such that the rear wheel cannot 
turn any faster than 312.5 revolutions per minute, and yet the horse¬ 
power required is just as great as though the rear wheel was turning 
at 625 revolutions per minute. The clutch is slipped sufficiently so 
the engine can run at its maximum speed of 2,500 revolutions per 
minute. The gear ratio between the clutch and rear wheel remains 
the same regardless of how much the clutch is slipped or 4 to 1. 

Therefore, in order to get a rear wheel speed of 312.5 revolutions, 
the clutch-driven members must turn at 1,250 revolutions. The 
difference between that speed and that of the plates driven by the 
engine (assuming that the clutch is mounted on the engine shaft) is 
1,250 revolutions per minute, which means that the clutch is slipping 
sufficiently to permit of the loss or actual waste of 50 per cent, of the 
power of the motor. The effective power output cannot be based on 
the number of engine revolutions but upon the revolutions per 
minute of the member driving the wheel. If the engine is delivering 
12 horse-power to its crankshaft, but half that or 6 horse-power is 
being taken by the drive sprocket attached to the clutch member 



Power Transmission System Parts 


303 


turning at 1,250 revolutions per minute. The actual torque or horse¬ 
power available at the rear wheel must be based on the lower figure 
less the losses in transmission. Therefore, under conditions where 
the entire power capacity of the machine is needed to overcome resist¬ 
ance to motion, no form of slipping clutch can be effective because 
the diminution in rear wheel speed can only be obtained by wasting 
power represented by the revolutions of the engine lost in slip between 
the clutch members. At the other hand, the intermediate reduction 
gearing of the two-speed gear transmits power rather than losing it 
because it is positive and not flexible, and, while no gearing will work 



Fig. 166.—Showing the Location of the Planetary Two Speed Gear on 

the Excelsior Motorcycle. 


without friction, the loss of energy through this added resistance is 
not to be compared with that wasted through clutch slip. While a 
friction clutch wall provide variation of speed between rear wheel and 
engine shaft, it does this only at the expense of lost power, and a 
friction clutch is only effective for maximum power transmission when 
the clutch members are locked together and when clutch slipping is 
at a minimum. A reduction gearing reduces the speed without slip 
or loss other than that produced by the friction of gears and their 
bearings. It will be obvious that any claims where the friction clutch 
is given the same value as the reduction gear for obtaining varying 









304 


Motorcycles , Side Cars and Cyclecars 


effective reduced speed ratios are absurd. The ideal combination is 
that of the reduction gearing and friction clutch, because with the 
two, we are able to obtain all the good features desired. We can slip 
the clutch on the level to slow up the machine, yet, when a hill or 
poor road confronts us, the reduction gearing may be brought in action 
to transmit power positively. 

Change=Speed Gear Location. —As most forms of change-speed 
gearing are combined with a clutch, the usual method of location is 
the same as that which obtains with the friction clutches previously 
described. The simpler forms such as variable speed pulleys and 
some forms of planetary gearing are usually attached to the engine 
crankshaft. The most common location is at the crank-hanger where 
the change-speed gearing takes the place usually occupied by the 
simpler friction clutch. In some cases, the change-speed gear is in¬ 
corporated as a unit with the power plant, though in most machines 
it is a separate mechanism distinct from the engine. 

When change-speed gearing is employed, it is possible to dispense 
with the usual pedal starting gear, though it must be replaced by some 
equivalent device such as a kick starter or hand crank such as used on 
automobiles. The Indian motorcycle is made in one model “de luxe” 
with ah electric self-starter very similar in action to those employed 
in automobiles. When the pedaling gear is eliminated, the control 
of the motorcycle is the same as that of an automobile, as the drive 
is interrupted by shifting a clutch instead of by raising the exhaust 
valves or interrupting the ignition as was formerly the practice with 
direct drive single-gear machines. The application of a kick starter 
to a modern two-speed motorcycle is clearly shown at Fig. 155, and 
in this construction the change-speed gearing replaces the usual 
crank-hanger. In the machine shown at Fig. 166, the variable speed 
gearing is used in connection with the pedal-starting lever, and is 
mounted as a countershaft, replacing the conventional friction clutch 
assembly widely used at that point. 

In the Harley-Davidson motorcycle, shown at Fig. 167, the two- 
speed gearing is incorporated in the rear hub instead of being attached 
to either the crank-hanger or the engine shaft. The same reasons 
that are given for friction clutch location apply just as well as the 
two-speed gear, and the slower the parts turn the larger and more 


Power Transmission System Parts 


305 



substantial they must be to transmit the same amount of power. An 
engine shaft gear can have much smaller parts than a rear hub type, 
but, as is true of friction clutch design, a compromise between these 
two extremes is favored by most designers, and the speed gearing is 
installed at the crank-hanger in the form of countershaft where the 
speed of rotation is about half that of the engine shaft, and in some 
cases nearly twice as much as the rear wheel velocity. 

Variable Speed Pulleys. —The simplest form of variable speed 
gear which involves the use of belt drive is the expanding V-pulley. 
A simple form in which the variation is obtained only when the pulley 


Fig. 167.—The Harley-Davidson Eight Horsepower Twin Cylinder 
Motorcycle, With Two Speed Gear in the Rear Hub. 

is adjusted by the rider is shown at Fig. 168. In this, a fixed flange 
is attached to a hub that is provided with one large thread to receive 
the adjustable flange, and with a thread of smaller diameter to fit the 
locking member. The main portion is secured to the engine crank¬ 
shaft. When the pulley is assembled, the nearer the flanges are 
together the higher the gear ratio, because the belt is forced to drive 
at the top of the flanges. As the flanges are spread apart, the belt 
can drop lower, and as it fits a portion of the pulley of lesser diameter, 
the ratio of drive will, of course, be lower than when it is at the top 








300 


Motorcycles , Side Cars and Cycle cars 


of the pulley. The adjustment of the flange is a simple matter, as it 
involves merely the release of the locking member and the movement 
of the flange on its thread to the desired point. When the proper 
degree of adjustment has been secured, the locking member is set up 
tightly against the adjustable flange and maintained in position by it. 

At Fig. 169, a pulley is shown that is said to compensate auto¬ 
matically for increased resistance at the driving wheel by providing 
a lower gear ratio. In this, the movable flange member is forced 


Vox* N 



PoWey AssemUy 
CCoTTvp\e-\.C' •) 


Uo 


cV\n<£ 



V\) ceci F\&Y\<5e, 


Fig. 168.—Construction of Simple Adjustable Pulley for V Belts. 


toward the fixed flange by a series of coil springs, and it is claimed 
that as the resistance increases the belt tension becomes greater and 
forces the flanges apart until a point is reached where the ratio of 
drive has been reduced to the proper value. Variable pulleys of this 
form are provided with an auxiliary operating means which can be 
used to provide a lower gear ratio or a free engine independent of the 
resistance if desired. 

The complete installation of the Auto-Varia, which is of English 














































































Power Transmission System Parts 


307 


design is shown at Fig. 170. A pulley control roll is mounted at the 
lower portion of a control handle, the upper end of which works in 
a sector attached to the frame. The function of the roll is to force 
the movable flange of the pulley outward when it is desired to obtain 
the lower ratio, and to spread the flanges so far apart that the belt 



Fig. 169.—The Auto-Varia Pulley for V Belts. 


will ride on a free, ball bearing supported ring at the bottom of the 
pulley when a free engine is desired. A variable pulley with which a 
friction clutch is included is shown at Fig. 171. This is a Rudge- 
Whitworth design and is said to give very satisfactory results. The 
action is the same as that of the simpler forms, means being provided 
for actuating the clutch that are independent of those available for 





































































308 Motorcycles , Side Cars and Cyclecars 



Fig. 170.—Shov/ing Practical Application of the Auto-Varia Pulley and 

Control System. 


varying the position of the movable pulley flange. With the driving 
belt in the position shown the flanges are spread apart as far as they 
will go, and the lowest ratio of drive is obtained. This device is rather 























Power Transmission System Parts 


309 


more complicated than some of the simpler forms that are said to 
give fully as good results in practice. 

Engine Shaft Gear. —A two-speed and free engine planetary gear 
of English design, and sold under the trade name of “Fits all,” is 
shown at Fig. 172. While the arrangement is such that the drive is 
by means of V-belt, it is possible to replace the belt pulley with a 
























































































































310 


Motorcycles , Side Cars and Cyclecars 



Fig. 172.—Sectional View of Typical Planetary Two Speed Gear, 
Adapted for Application to Engine Shaft. 


sprocket, and obtain chain drive. The action of this gear is simple, 
and, if thoroughly understood, it will serve to make clear the prin¬ 
ciples underlying speed reduction by all forms of planetary gear sets. 
A main driving member that carries the assembly is securely keyed 
to the engine shaft A and is held firmly in place by a threaded shaft 
extension that forms an auxiliary support for the gear assembly. 
When the parts are in the position shown in the sketch, the engine 

















































































































































































Power Transmission System Parts 


311 


may turn without driving the rear wheel because the main driving 
gear will rotate the planetary reduction gears L around on the bearing 
stud on which they rotate without producing any movement of the 
pulley I. If the friction band G is clamped around the drum H to 
keep it from turning, while the planetary pinion assembly L will turn 
on the stud, the pinion carrier H cannot rotate and the planetary 
pinions therefore serve as an intermediate gearing connecting the 
main drive gear with the pulley drive gear B. The main drive gear 
is about the same size as the larger gear of the planetary pinion 
assembly and therefore turns it at about the same speed. The small 
gear of the planetary pinion assembly is smaller than the driving 
gear B with which it meshes so a reduction in speed is possible between 
the belt pulley I and the engine shaft A due to the difference in size 
between gears B and the small member of the assembly L.' While 
but one spur pinion assembly is shown, most planetary gears use two 
or more sets spaced equally around the casing H in order to equalize 
the driving strain and prevent wear on the bearings that would be 
unavoidable if but one set of intermediate pinions was employed. 
When it is desired to obtain the direct drive, the brake band G is 
released and the high speed clutch plate F is firmly pressed against 
the side of the drum H by a face cam and ball thrust arrangement, 
controlled by the rider, and the entire assembly is thus locked together 
as a unit so the drive is direct from engine shaft A to the drive pulley I. 

Countershaft Gears. —Countershaft gears are made in infinite 
variety, and they may form part of the power plant unit or be attached 
to the crank-hanger. The views of the De-Luxe motor at Figs. 173 
and 174 show clearly the external appearance of a two-speed gear of 
the countershaft type when it forms part of the power plant. This 
makes it possible to utilize the regular pedal-starting gear, if desirable, 
as the change-speed gearing is placed forward of the crank-hanger 
and is independent of it. Where the change-speed gearing is not a 
part of the engine case and must be supported from the crank-hanger, 
it is sometimes impossible to utilize the pedal gear for starting the 
engine, so an auxiliary starting-crank arrangement, such as shown at 
Fig. 175, must be used to turn the engine crankshaft over and start 
the motor. 

The arrangement may be easily understood from the illustration. 



Motorcycles , Side Cars and Cyclecars 


31 2 

The view at A shows the starting crank in place with the jaw clutch 
making a suitable connection between the starting-handle shaft and 
the main gear shaft, as soon as the engine starts the handle is auto¬ 
matically released, and a coil spring will force the starting clutch out 
of engagement so that the member to which the starting crank is 
attached does not rotate except when it is pressed into engagement 

with the clutch member 
by suitable end pressure 
on the starting handle. 

The arrangement of 
the clutch and change- 
speed gearing in the 
Michaelson unit power 
plant is outlined at Fig. 
176. In this, the mul¬ 
tiple disc clutch of the 
usual pattern is at¬ 
tached to an extension 
of the engine crank¬ 
shaft, and drives an in¬ 
termediate gear assem¬ 
bly consisting of two 
gears, one larger than 
the other, which in turn 
transmit the crankshaft 
motion to a suitable 
spur gear on the main 
driving shaft of the 
two-speed gearing. The arrangement of the gears in this variable 
speed member is practically the same as those shown at Fig. 
179. A shifting clutch member clutches either of the gears to the 
sprocket-drive shaft. The use of the intermediate gear member pro¬ 
vides for a first-speed reduction gear completely enclosed and running 
in oil. This power-transmitting element takes the place of the usual 
short chain that joins the engine crankshaft to the conventional 
countershaft gear arrangement such as outlined at Fig. 178. The 
engine is started by a small sprocket member that drives a suitably 



Fig. 173.—Carburetor Side of Spacke Two 
Cylinder Motor With Two Speed Gear 
Integral With Power Plant. 







Power Transmission System Parts 


313 


formed clutching member at one side of the gear case and which en¬ 
gages the main shaft of the change-speed gearing. This position is 
preferable to a direct application to the engine crankshaft because 
the engine is started through the intermediate gears, which insures 
that the crankshaft B can be maintained at a higher rate than would 
be possible by direct application of the starting handle, owing to the 

geared-up drive between 
the starting means and 
the crankshaft. In or¬ 
der to start the average 
motorcycle power plant 
promptly, it is necessary 
to rotate it at a fairly 
high rate of speed. 
This was always an im¬ 
portant advantage in 
connection with the 
u s u a 1 pedal - starting 
gear, because the rear 
wheel could be turned 
over fast enough by the 
feet to revolve the en¬ 
gine crankshaft at a 
higher rate of speed 
than is possible with 
most kick starters or 
equivalent devices. 
There are conditions 
where it is important to turn the engine over fast to secure 
prompt starting, such as in cold weather when the gasoline does not 
vaporize readily. The application of the geared-up starting crank 
gives practically the same rotative speed as would be obtained through 
the conventional pedal-gear arrangement. 

The Minneapolis power plant which is shown at Fig. 177 is similar 
in general arrangement to the Michaelson, but employs a distinctive 
means of speed changing. The transmission is of the planetary type 
using positive clutches for both high and low speed which, of course, 



Fig, 174.—Valve Side of De Luxe Unit 
Power Plant Showing Driving Sprocket 
on the Gear Box. 








314 


Motorcycles , Side Cars and Cyclecars 


is made possible by utilizing a master clutch on the engine crankshaft. 
A jaw clutch member is adapted to slide on a bushing surrounding 
the main shaft, and this may be engaged either with the member 
carrying the planetary reduction or it can be moved over to push a 
clutch member in engagement with the driving gear of the trans¬ 
mission shaft. When in the position indicated, the gear that drives 
the transmission shaft is clutched to that member. If the jaw clutch 
is moved to the other extreme, a series of projections extending from 



Starting Clutch 


Startii^ Clutch 

Male Member 


Clutch " “pi^' 
Release 
Lever 

Starting 
Handle 


Female Member 

' B 


Fig. 175.—Starting Handle Clutch Arrangement Used in Connection 

With Jardine Two Speed Gears. 


the face of the clutch shifter engage suitable depressions in the 
planetary gear-carrying plate, and keep that member from rotating 
because the jaw clutch shifter is securely anchored to a through bolt, 
extending from one side of the gear case to the other, which keeps it 
from rotation. When used in connection with planetar} 7 gearing, it 
takes the place of the usual band clutch, and the drive is then to the 
member carrying the driven spur gear inside of the case, and threaded 






































Power Transmission System Parts 


315 



\}rwe Sprocket 


S t stfk S prockek 


L:" ,: ''' 




,CraY\kc&se 


CranksW^t 


bump 


Ltotermedjab 
fceasT 


C\utc\i Case, 

CAiAcVi 


Sprocket 

Drive 




Fig. 176.—Showing Arrangement of Change Speed Gearing in Michael 

son Unit Power Plant. 























































































31G 


Motorcycles , Side Cars and Cyclecars 


on the outside to receive the driving sprocket. With this construction, 
it is imperative that the master clutch be released before either the 
high or low speed is engaged. 

The usual installation of a countershaft gear of the shifting jaw 
clutch type is shown at Fig. 178. At the bottom or plan view, the 
relation of the gear to the engine base, and the method of driving 
from the engine crankshaft, is clearly shown. A compensating clutch 
at the engine crankshaft is utilized to prevent depreciation of the chain 
through unsteady power application and from the sprocket mounted 
on that member, the drive is by chain to the sprocket attached to the 
main clutch member that forms part of the countershaft gear. The 
drive to the rear wheel is from the smaller sprocket on the counter¬ 
shaft to a suitable member on the rear hub. The method of shifting 
the speed is also depicted, the jaw clutch controlling the two speeds 
is operated from a small lever attached to the top frame tube which 
works on a notched quadrant providing three stops for the lever. 
The center one is in neutral position, and at such times as the small 
lever stands vertically, the shifting clutch in the transmission interior 
is at a point between the two engaged positions. Moving the lever 
to one extreme or the other will engage the high or low speed re¬ 
spectively. The clutch is shifted by a foot pedal attached to the 
bottom of the bracket supporting the power plant. 

The interior arrangement of the Indian two-speed gear, which is 
representative and the original of all the shifting clutch forms, is 
shown at Fig. 179. A friction clutch of the regulation Indian pattern 
serves as a master clutch, and the drive from the engine is directly 
to a large driven sprocket attached to the clutch casing. A driven 
shaft passes through the center of a hollow quill or bushing, at one 
end of which the drive sprocket that transmits the power to the rear 
wheels is secured, while at the inside a spur gear is mounted. The jaw 
clutch is keyed to this shaft which is supported at its other end by a 
ball bearing. This shaft is also hollow, and the clutch release rod 
passes through the center of it. The jaw clutch member is adapted 
to be shifted from its central position to either the right or left to 
engage suitable teeth projecting from the face of the two gears. The 
gear that is attached to the bushing carrying the sprocket meshes 
with a smaller member carried on a countershaft to one side of the 


Power Transmission System Parts 317 



Fig. 177—Views Depicting Construction of the Minneapolis Unit 

Power Plant and Gearset. 


main shaft. A larger gear on the countershaft meshes with a smaller 
member that is normally free to revolve on the main shaft, and which 
is independent of it at all times except when the jaw clutch is moved 
over to engage with the teeth on its face. 







































































































































































































































318 


Motorcycles , Side Cars and Cyclecars 



«ssn 


ATf.Hr 


Ciuteh Shifter 
CjutcK - || 


Fig. 178.—Methods of Installing the Jardine (English) Countershaft 

Type Two Speed Gear. 

With the jaw clutch in the position shown, even if the master clutch 
is engaged, the rear wheel will not turn because the sleeve carrying 
the drive sprocket does not rotate. To obtain the low speed ratio, 
the jaw clutch is moved to the right to make fast to the shaft the 
smaller of the gears mounted on that member. The drive is then 
from the clutch to the small gear, which, in turn, drives the large 
gear on the countershaft at a lower rate of speed. The other gear 


Two Speed 'Top Frame Tube 

Gear First Reduction P 


Speed Chag5in£ 
Lever 


\ Chain Motor 


u€dP 

Shifting ' 
Rod . 


\ MotorDnVe 

Sprocket 

Friction 
Cushioning Clutch 
MotorBase 


//• -V 

1rxV • 

1 


1 h 

'.({ ■■ A • ' 4 

;i ( 

. I tt . f T 

' ; l! i \ 

a ' v 

A • ■ , / : 1 



.. ..jit... —- • _ii.. 

——... - 


Change 
5peed Gear 


Clutch Shifter 



























Power Transmission System Parts 


319 


member on the countershaft is smaller than the sprocket drive gear, 
and a further reduction of speed is possible between these two. The 
driving sprocket is turning in the same direction as the main shaft, 
but at a lower rate of speed on account of the reduction gears inter¬ 
posed between the sprocket and the clutch-driven shaft. To obtain 
the high-speed ratio, the jaw clutch is moved to the left, and makes 
the sprocket-drive gear fast to the main shaft. This means that the 
driving sprocket would turn at the same speed as the main shaft to 
which the clutch is attached. The master clutch is shifted by a 



Sprocket DmeCitav Taw Clutch 


r AV \ 


■ 


-Counter 


Omen Sprocket Connected 
To ttator 


Clutch 

Spring 


Clutch Discs 


Drive Sprocket 


- 


Fie 179 —Sectional View Showing the Two Speed Individual Clutch 
Gear and Master Clutch of the Friction Type Employed on the 
Indian Motorcycle. 









































































320 


Motorcycles, Side Cars and Cycle cars 


releasing worm that exerts pressure against a rod passing through 
the center of the main shaft, and attached to the outermost clutch 
plate. When this plate is moved to the left, the clutch springs are 
compressed, and the driving pressure between the plates is inter¬ 
rupted. It is necessary to release the master clutch at all times that 
the jaw clutch member is shifted, because if the positive clutch is 
moved -with the friction clutch engaged it will start the motorcycle 
so suddenly that the parts of the transmission system may be stressed 
to the breaking point. 

Another form of countershaft variable speed gear is shown at Fig. 
180. This differs from the type previously described, in that it is a 
sliding gear form and provides three forward speeds instead of two as 
is common practice. The power from the engine is delivered to the 
clutch case by the sprocket A, and the inner member of the clutch is 
attached to and drives the main shaft B of the transmission. A sliding- 
gear D is mounted on the main shaft, and is provided with clutch pro¬ 
jections E on both sides. When the member D is moved to the 
extreme right of the gear case, the projecting teeth E clutch corre¬ 
sponding members on the small spur gear G, thus locking the gear G 
to the main shaft. The gear G is considerably smaller than the gear L 
mounted on the countershaft H, and turns that member at a lower 
rate of speed. The driving sprocket M is attached to a bushing to 
which the sprocket-driving gear is securely fastened. The constant 
mesh gear on the countershaft H that meshes with the gear F is smaller 
than that member, and thus a further reduction in speed is obtained. 
The driving sprocket M turns at a considerably lower speed than the 
main driving shaft B, owing to the two reductions obtained, one 
between the gears G and L, and the other between the small constant 
mesh gear on the countershaft and the sprocket gear F. If the sliding 
member B is engaged with the member K on the countershaft there is 
but one reduction in speed, and that is between the constant mesh 
gears, because the gears D and K are practically the same size. This 
is an intermediate ratio that is not as slow as the low speed, and yet 
is slower than the direct drive. 

If the sliding member D is moved to the extreme left, the clutch 
teeth E-l will engage suitable members projecting from the gear F, 
and will lock the sprocket drive gear directly to the main shaft and 


Power Transmission System Parts 


321 


obtain a direct drive. With this form of transmission, it is even more 
important to release the master clutch before speed changes are 
effected than it is with the sliding clutch forms in which the gear teeth 
are always in mesh. If the sliding member D is moved into mesh 
with the gear K, with the clutch engaged, it will be apt to produce 
serious damage to the teeth of the two gears, because it is almost im¬ 
possible to mesh spur gears when both are in motion. A kick starting 



Fig. 180.—English Three Speed Countershaft Change Speed Gearing 

of the Sliding Type. 


gear is incorporated with this gear-set. The pedal crank P which is 
adapted to be pushed by the foot of the rider is clutched to the geai N 
which meshes with a much smaller gear 0 attached to the main shaft 
B. Even if the pedal P is only moved through a small portion of a 
revolution, the engine shaft will be turned several times on account 
of the gearing of the starter as well as the step-up between the large 
sprocket A on the clutch and the smaller member on the engine shaft. 






























































































































322 


Motorcycles , Side Cars and Cydecars 



Rear Hub Gears. —Several forms of rear hub gears have been 
applied, and these are practically all of the planetary type. That 
shown at Fig. 181a, in cross section, and at Fig. 182, in partial dis¬ 
assembly, is used on the Thiem motorcycle, which is an American 
design. The gear itself is patterned very closely after a popular 
English two-speed hub. The method of obtaining the low speed by 
the use of planetary reduction gears is practically the same as that 
employed in the engine shaft gear shown at Fig. 172. A suitable 
brake band clutches a drum securely fastened to the axle, and one 


Fig. 181 .—Novel Method of Speed Reduction by Bevel Gearing 
Incorporated in the Harley-Davidson Two Speed Hub. 

of the main gears of the planetary reduction is also keyed to the 
axle. The other sun gear, as the central main member is called, is 
attached to the hub member proper. The drive from the motor is 
by V-belt to a pulley rim laced to the drum carrying the planetary 
reduction gears by the conventional wire spokes. When it is desired 
to apply the low speed, the brake band that works on the outer drum 
is constricted and holds that drum and the axle to which it is fastened 
stationary. The planetary pinions are free to revolve on their retain¬ 
ing studs and drive the hub shell because they must turn it in the 
same direction, though at a slower rate of speed, than the pulley rim 
















323 


Power Transmission System Parts 


9m\onTiKcd 
"Id (V*»W 


C 


If 


*Wr Pinion 

Dritfinj Hub 
WvA> 




.*jfcSSto 

D\te<A 0*We C\u\oVv 
, V.ONW S'pe^d 


‘PlftYieVaivx Fin \ on. / l . c , _ 

Cw^ief CB tdXa Band 


Fig 181a.—Sectional View of the Thiem Two Speed Rear Hub. 


travels on account of being forced to roll around the spur gear keyed 
to the axle. To obtain a high speed, an expanding band clutch is 
engaged by leverage actuated by a shifting cone, and the entire hub 
assembly is locked to, and must turn with the axle. The principle 
of this gear may be more easily grasped if one remembers that the 
axle travels forward with the road wheel when in high speed or direct 
drive position; that it is held stationary when in low speed and that 
it will revolve backward when in the neutral or free engine position. 
The inner brake band serves as a running brake, and will retard the 
hub positively whether the gearing is in use or not. 





















































































































































































324 Motorcycles , Side Cars and Cyclecars 

A distinctive form of reduction gear mounted in the rear hub is 
that used in connection with the Harley-Davidson motorcycle. The 
gearing is of the bevel form and operates on the planetary principle. 
A shifting dog clutch is employed in addition to the master clutch 
which is of the friction type. When moved in one position, the master 
clutch chives tlue hub directly, and when it is pushed to the other 
position it drives the hub through the medium of the bevel-speed 
reduction gear. The complete device is not shown in the illustration 
(Fig. 181), as a clutch assembly and a friction brake must be added 
to the simple hub shown to complete the mechanism. 



Fig. 182.—The Thiem Two Speed Hub Partially Disassembled to 

Show Arrangement of Mechanism. 


Forms of hub gears working on the planetary principle have been 
evolved abroad which provide three forward speeds, but these are so 
complicated that they have received practically no application in 
America. There seems to be no good reason for the use of three-speed 
gears unless the motorcycle power plant lacks capacity, and, as the 
best American practice seems to be to provide a two-speed gear more 
for emergency use and to use power plants that will have sufficient 
power to overcome practically all normal resistance on the direct 
drive or high gear, the low gear is to be used only for starting, in hill 
climbing or in negotiating unfavorable highway surfaces. Practically 
all of the time the motorcycle is in use it may be operated on the 











Poiver Transmission System Parts 325 




























































































































































326 Motorcycles , Side Cars and Cyclecars 

direct drive or high speed. Fitting an intermediate ratio between 
the high and the low is not necessary when the power plant is of 
suitable proportions, though it might be of some value if the machine 
was under-powered, and the direct drive could only be used under 
exceptionally favorable operating conditions. 

The Sturmey-Archer is a typical example of a three-speed hub, 
and it is said that the lowest gear ratio is to be used only when ex¬ 
tremely high resistance must be overcome. The internal construction 
can be clearly understood by referring to Fig. 182a. When on the 
high gear, all parts of the hub are locked together solidly as the hub 
shell is driven directly from the driving member. On the second or 
intermediate gear, the drive is obtained from an internal gear member 
which rolls planetary pinions around a stationary central gear integral 
with the axle. The reduced motion of the planetary pinions is trans¬ 
mitted to the wheel hub by a driving member that clutches extensions 
from the friction clutch carrier. When the lowest gear of all is brought 
into action, the drive is through still another set of pinions and a 
further reduction in speed is effected. The direct drive is obtained 
by a plate clutch in the hub interior. It is said that a reduction of 
47 per cent, in speed is obtained on the intermediate speed, and that a 
further reduction of 40 per cent, is secured on the low speed. The 
various speed changes are effected by moving a laterally shiftable 
member to the right or left, and the lowest speed ratio is obtained as 
the member is moved to the right. When on the high gear, the cup- 
shape driven member engages projections which are on the rim of 
the circular or internal gear member driven by the belt pulley. This 
means that the high gear is direct from the drive pulley carrier to the 
plate clutch. When the intermediate speed is desired, the sliding 
member engages with the internal gear carrying the first set of planet¬ 
ary" pinions, and this internal gear meshes with and drives the second 
train of planetary pinions. On the lowest speed, the driven member 
engages with the carrier of the second set of planetary pinions. 

Three Chain Systems. —A form of two-speed gear that has been 
used with some degree of success on European motorcycles is that 
shown at Fig. 183, in which a double sprocket is attached to the engine 
crankshaft, and two chains extend to the sprockets on the counter¬ 
shaft. Each of these sprockets may revolve independently of the 


Power Transmission System Parts 327 

other or both may revolve free of the smaller driving sprocket used 
for driving the rear wheels. It is said that an advantage of this type of 
gear is that both speeds are direct and the friction and power loss due 
to the use of gear pinions is not present. It is also advanced that this 
system is extremely quiet in action, and that the clutches, which are 
of the internal expanding type may be used to give a free engine on 
either gear ratio. 

The original form is undoubtedly the Phelon & Moore, which is 



shown at Fig. 183. The low-gear sprocket, which is the largest, is 
the outside member, while the high-gear sprocket, which is the smaller 
of the two large ones, is the inside member. The clutch members act 
as bearings on which the sprockets revolve when the gear is in neutral 
position, but when expanded the shoes grip the interior of the drum 
carrying the sprockets very tightly and transmit the power to the 
small sprocket to which the brake shoes are fastened. The internal 
clutches are brought into engagement by sliding a wedged-shaped 
member to the right or left as the case may be, and spreading out the 











































































































328 


Motorcycles , Side Cars and Cyclecars 


brake shoes. In the form shown at Fig. 183, if the wedge bar is 
moved to the right, the brake shoe that clutches the high speed 
sprocket will be expanded, and the drive will be from the engine shaft 
to the countershaft through that member, while the low gear or larger 
sprocket will revolve freely on the brake shoes that are not expanded 
and which therefore act as a bearing for that member. If the wedge 
bar is moved to the left, the outside sprocket will be clutched to the 
driving member, and the smaller or high-gear sprocket will revolve 
freely on its brake shoes. It would seem that there would be con¬ 
siderable wear due to the movement of the sprocket carrier over the 
brake shoes, but the successful use of this form of change-speed gear 
for a number of years indicates the large surface of the bearing and 
the provisions made for lubricating them are adequate to prevent 
untimely depreciation. 

The two-speed gear used on the Enfield (English) motorcycle is of 
the same pattern and is clearly outlined at Fig. 184. Either gear 
ratio may be brought in action by expanding the hardened steel 
bands A into one of the drums B, also of hardened steel, to which the 
chain wheels C are secured. The change in gear ratio is obtained in 
the same manner as in the Phelon & Moore by driving through the 
large sprocket for low speed and through the smaller sprocket for 
high speed. The expanding bands A are carried on internal drums D 
which take the drive, and which are keyed on the ball bearing shaft E 
that is employed to drive the sprocket F that connects with the rear 
hub. The clutches are engaged by cams cut into the block G, which 
is capable of sliding in either direction according to which gear is 
desired. The action of the cam is to force one of the pegs H against 
the split roller I, which forces open the band A until it engages with B, 
which is rotated by the engine. The object of splitting the roller I 
is to permit the clutch to pick up smoothly. The block G which 
contains the cam is moved by the rack J and the pinion K, which is 
operated by a vertical shaft and lever at the top of the crank. Three 
pairs of cams numbered 1, 2, and 3 are cut in G, each of these being 
.005 inch higher than the one preceding it. Should the band A wear 
to such a point that cam A is not sufficiently high to operate it, the 
member G may be turned around so the next larger cam will be 
used to expand the brake band. The practical application of 


Power Transmission System Parts 


329 



Fig. 184.—Two Speed Countershaft Gear Used on the Royal Enfield 

Motorcycle. 

this gear to a Clement (French) motorcycle is clearly outlined at 
Fig. 185. 

Planetary Countershaft Gear .—Several of the American motor- 




















































































































































330 


Motorcycles , Side Cars and Cyclecars 


cycles employ a planetary reduction gear mounted on an extension 
projecting from the crank-hanger. A successful form, which is used 
on the Excelsior motorcycle is shown at Fig. 18G. The drive from 
the motor is to the sprocket B attached to the planetary gear carrier 
A which also forms the male member of the friction clutch employed 
for direct drive. When it is desired to obtain a low speed ratio, the 
female member of the high speed clutch is pulled out of engagement 
with the male member, which is fixed and the V-shape bronze brake 



Fig. 185.—Three Chain Speed Changing and Driving System Used on 

Clement Motorcycle. 


band M is tightened around the carrier I, to which is attached the 
gear H. As this gear is held stationary, the planetary pinions must 
rotate on their studs as they are carried around by the member A, 
and, as they turn at the same time, they drive the gear E, which is 
securely keyed to the bushing to which the sprocket G is fastened. 
To obtain a high gear ratio, the member M is released and the female 
member J, of the cone clutch, is brought into engagement with the 
male member so the drive is direct from the sprocket B through the 







331 


Power Transmission System Parts 

clutch members to the member F to which the wheel driving sprocket 
C, is keyed. The member J is actuated by the operating worm K 
which is oscillated by the lever L. The entire construction is mounted 
on ball bearings so but little friction is present, and the liability of 
bearing depreciation is proportionately reduced. The practical in¬ 
stallation of this gear, and the method of operation by a single handle, 
is clearly shown at Fig. 166. If the handle is moved in one direction 
the low speed is applied, and in the other position the high speed will 



Fig. 186.—The Substantial Two Speed Planetary Gearset of thoj 
Countershaft Type Used on Excelsior Motorcycles. 


be engaged. When in the position shown or approximately at the 
center of the notched quadrant, the gear is in the free engine position 
as neither the high-speed clutch J nor the low-speed friction band M 
is in engagement with their respective co-acting members. 

Sliding Gear Type .—The sliding gear forms which have been so 
generally used in automobile practice have received but limited ap¬ 
plication in motorcycles. This is not as popular among motorcycle 
designers as the individual clutch systems are, because considerable 


































































332 


Motorcycles , Side Cars and Cyclecars 


damage may result to the transmission gear when handled by the 
inexperienced rider. If attempt is made to change the speeds without 
releasing the main clutch member, the gear teeth will be burred or 
destroyed entirely. These pieces may get into the transmission and 
wreck the entire construction. It is contended by those who favor 
this construction that there is no more reason for the motorcycle 
rider to damage a transmission than there is for the automobile 
operator. As a general rule, the motorcycle is not intended to be 



Fig. 187.—Pierce Two Speed Sliding Gear Transmission. 


handled b} r expert mechanics, and the simpler the control system the 
more popular the motorcycle will be. In the individual clutch form, 
notably in the two-clutch planetary types, one cannot obtain a speed 
ratio without first declutching the engine. In the sliding gear, forms 
that are patterned after automobile practice, it is possible to shift 
gears whether the clutch is released or engaged. 

A simple and effective sliding gear system which has been success¬ 
fully used on Pierce motorcycles is shown at Fig. 187 with a portion 






Power Transmission System Parts 


333 


of the gear case cut away to show the arrangement of the sliding 
members, and in section at big. 188 so that the method of actuating 
the sliding members and the friction clutch simultaneously may be 
readily ascertained. This sliding gear transmission does not have the 
main disadvantage to that form of gearing, because when the shifting 
member is moved from one gear ratio to the other, the clutch is 
released automatically by the double cone arrangement, and will not 
be fully engaged until the shifting member is completely in mesh with 
one or the other of the gears attached to the propeller shaft. 



Fig. 188.—Plan View of Pierce Two Speed Sliding Gearset. 


Power Transmission Methods. —A point on which considerable 
difference of opinion has always existed has been the best method of 
conveying the engine power to the traction member of the motorcycle. 
At the present time, belt, chain and gear drive are all used, and various 
combinations of these three forms are sometimes used in conjunction. 
Some systems of power transmission are more efficient than others, 
and, as a rule, those that are the most positive and that will transmit 
the engine power with minimum loss due to slipping are also apt to 
























































334 


Motorcycles , Side Cars and Cyclecars 


have other disadvantages which would tend to favor the forms where 
the drive was by more flexible means. 

The two conventional methods of driving a motorcycle are out¬ 
lined at Fig. 189. The first system to be applied, and the one that 
was formerly the most popular, is by leather belt, which may be any 
one of a variety of forms. The type illustrated is a flat belt of the form 
that has been so widely used in driving the machine tools of the 
mechanic, and practically all other forms of machinery for many years. 
The other, which is more positive, involves the use of chains and 
sprockets. The latter method of driving was used on the first auto¬ 
mobiles, just as soon as it was definitely determined that the flat belt 
drive systems were not practical for the heavier forms of four-wheeled 
vehicles. These systems will be considered more in detail in proper 
sequence. Drive by gearing is general at the present time in auto¬ 
mobile practice, and is followed to some extent by motorcycle de¬ 
signers. Either the bevel or worm gear drive may be used in con¬ 
nection with a shaft extending from the power plant. 

The single-belt drive, either by means of flat or V-belt is the 
simplest power transmission system, because it is possible to obtain 
a degree of free engine action without the use of a clutch if a jockey 
pulley or idler is employed to tighten the belt. With a V-belt, it is 
necessary to use a free engine clutch of some form to obtain the free 
engine which is also true of the various positive driving means such 
as chains and gears. The system of transmission to use depends to 
a large extent on the individual preferences of the rider and designer, 
because each system has its advantages, and all have been proven 
practical. When it comes to a question of efficiency, the drive by 
single chain or V-belt is undoubtedly the one that will transmit power 
with the least loss. With a properly adjusted V-belt, there is prac¬ 
tically no slipping, and a flexible drive is obtained. A certain amount 
of power is required to bend the belt over the pulleys, but this is prob¬ 
ably no more than would be consumed by friction of the various 
members of the chain and the friction between the chains and 
sprockets. 

The figures in the following table have been generally accepted by 
automobile designers, and apply just as well to similar driving systems 
used in motorcycle practice. 















336 


Mof or cycles, Side Cars and Cycle cars 


TRANSMISSION EFFICIENCY OF DIFFERENT TYPES OF MECHANISM 

(WORBY BEAUMONT) 


Source of Loss of Power. 

Amount of 

Loss 

Per Cent. 

Efficiency 
Per Cent. 


.... 

100.0 

When driving direct: 



One chain. 

3.0 

• • • • 

One and one-half pairs of bearings. 

7.5 

89.5 

With epicyclic speed gear in operation, add 

15.0 

74.5 

When driving direct: 



One set of gear. . 

5.0 

... * 

Two pairs of bearings. 

10.0 

.... 

Partial^ active bearings. 

3.0 

82.0 

With change-speed reduction gear in opera- 



tion, add. 

12.0 

70.0 

t 

« 


Carefully made brake tests have demonstrated that the power loss 
with a single-chain or V-beit drive is not greater than 10 per cent., 
whereas with a double-chain arrangement, which is the one generally 
used, about 20 per cent, of the power is lost in transmission. The 
type of change-speed gearing used also has some bearing upon the 
efficiency of the driving system. Gears of the planetary type will 
lose more power when on the low speed ratio than will either the 
sliding gear or sliding clutch forms, but at the other hand there is 
practically no loss when on the high speed because the assembly turns 
as a unit and the only power consumed is at the bearings. In either 
the sliding clutch or sliding gear forms, the countershaft is always in 
action due to the constant mesh gears, and some power is consumed 
at that point in addition to the main bearings. 

While the positive driving systems are the most practical, some 
unconventional systems of propulsion have been devised and tried 
out in an experimental way. These are usually in the form of attach- 






















Power Transmission System Parts 


337 


ments intended for application to the ordinary foot-propelled bicycle 
to convert it into a power-propelled type. One of these, which was 
exhibited at the recent motorcycle shows, is shown at Fig. 190, and 
propulsion is obtained by an air propeller of the same type used in 
aeronautical practice. It is said that with the latest forms of air 
propellers, more power can be obtained with a given engine size than 
will be delivered by marine propellers working in water. It is also 
claimed that the efficiency of a marine propeller will rarely rise higher 
than 60 per cent., while aeroplane propellers working in air may be 



90 per cent, effective. The air propeller of the device shown at Fig. 
190 has but little more spread than the span of the average bicycle 
handle-bars, and when used in connection with the small motor shown, 
the thrust is sufficient to push an ordinary bicycle 30 miles per hour 
over good roads. The engine is a three-port, two-cycle type, and 
with a bore of V/i inches and a stroke of 2}/i inches, at a speed of 
2,500 revolutions per minute, develops power ample for the purpose. 
The engine weighs but 16 pounds, and the entire attachment, includ¬ 
ing propeller, ignition system and fuel tank is said to weigh less than 









338 


Motorcycles , Side Cars and Cyclecars 


\ _ Snc^cAt . 


Cvr\iuretor 


40 pounds. While this system of propulsion is practical in air and 
marine craft and may have some degree of merit, it does not appear 
to be anything more than freak construction, and is only illustrated 
to show an unconventional method of bicycle propulsion. Such de¬ 
vices cannot give the satisfactory service obtained from properly 
designed motorcycles as the average bicycle frame, tires, etc., are not 

built with the idea of at¬ 
taching mechanical 
power. 

The Wall Auto Wheel, 
which device is of English 
design, illustrated at Fig. 
191, has considerably 
more merit than the air 
propeller, and has re¬ 
ceived practical applica¬ 
tion abroad. It consists 
of a separate wheel to 
which a miniature power 
plant is attached, and it 
is intended to be secured 
to the rear frame of a 
bicycle parallel with the 
rear wheel. The engine 
is air-cooled and has a 
bore and stroke of 2J4 
and 2 Vo inches respect¬ 
ively. It is claimed that 
it will develop one horse¬ 
power, which is said to 



me 


Frame 


Jrac\\oh 


Fig. 191.—The Wall Auto Wheel, a Com¬ 
plete Self Propelling Power Plant In¬ 
tended for Attachment to Ordinary 
Pedal Cycles. 


be ample to propel a bicycle at safe speed. The engine is 
of the four-cycle type, has an external fly-wheel, and includes a 
simple form of two-speed gear in an extension of the motor crank¬ 
case. 1 he drive from the two-speed gear to a sprocket mounted 
on the wheel hub is by means of a short roller chain. The wheel is 
22 inches in diameter and is carried in a substantial tubular frame¬ 
work to which the motor and fuel tank are secured. 














Power Transmission System Parts 339 

This device has been produced for more than five years by the 
manufacturers, which have a factory in London, and, while it is not 
claimed that it will give the same results as a regularly designed 
motorcycle, still it permits of converting a pedal cycle into a self- 
propelled form, and on level roads and in practically all city work, 
it will undoubtedly be able to furnish power enough to drive the 
bicycle without any muscular exertion on the part of the rider. It 
is said that the two-speed gear makes it possible to climb all reasonable 
grades. An attachment of this kind can be used only on good roads 
and under favorable conditions, but the device is novel, thoroughly 
practical and probably will appeal to people of conservative tern- 

ft 

perament who will be satisfied with medium speed, and who do not 
intend to use the device in touring. The American rights have been 
acquired by a prominent manufacturer, and if it successfully 
stands the test that it is now undergoing it will be marketed^in this 
country. 4 

Belt Drive Systems. —Before describing the various systems of 
power transmission by belt, it may be well to review the advantages 
advanced by those who favor that form of transmission. One of the 
most important claims relates to the flexibility of belt drive and its 
power of absorbing the road shocks and machine vibration, which, 
it is contended, results in minimum depreciation of the power plant. 
It is also claimed that the reverse is true of the positive driving sys¬ 
tem which transmits the road shocks to the entire macliine. The 
belt running over pulleys is silent because if a flat belt is used it is 
endless, and there are no metallic parts to strike and click. A V-belt 
may have a metallic coupling but this does not come in contact with 
the pulleys, and is therefore equally silent. Another feature of belt 
drive is said to be the absence of complicated parts. The conven¬ 
tional form of belt transmission consists of two grooved or flanged 
wheels, a connecting belt and a coupling, if a V-belt; or an idler or 
jockey pulley, if a flat belt. When a belt stretches, the rear wheel 
may be adjusted to compensate for the increase in length. It is said 
that the rider of a belt-driven machine experiences no discomfort 
from any irregularities of motor operation, as the flexible belt will 
take care of sudden changes of speed. Should a motor stop suddenly, 
as by breaking or sticking of some of the important internal parts, 


340 


Motorcycles , Side Cars and Cyclecars 


a belt will slip sufficiently to enable the rider to retain his place on 
the machine. A rigid form of drive would be apt to result in a sudden 
stop, and throw the rider. 

The factor of cleanliness is also given some consideration by the 
belt enthusiast, and it is evident that belts are naturally more cleanly 
because they do not need the lubrication that is necessary with chain 
drive. With the various positive driving systems, it is imperative 
that the parts be maintained in absolute alinement or there will be 
considerable depreciation of the mechanism and loss of power. With 



Fig. 192.—Harley-Davidson Five Horsepower Single Cylinder Motor 

cycle With Flat Belt Drive. 


belt drive, any slight misalinement does not produce appreciable 
wear, and there is but little loss in transmission efficiency due to this 
condition. It is the belt that depreciates and not the pulleys, as 
these frequently outlast from three to five belts before they become 
worn enough to reduce the efficiency of the drive. If one considers 
the chain transmission, defective alinement means that the chain or 
sprockets, and in most cases both, will wear unduly, and have a 
material reduction of the useful working life. When a chain or its 
sprockets are worn, efficiency of drive can only be restored by renew¬ 
ing both members. It is a known fact among mechanics that a neAV 












Power Transmission System Parts 341 

chain will not work well on worn sprockets, nor will an old chain 
function properly on new sprockets. The following summary of the 
advantages of belt transmission is given by a prominent manufacturer 
of these elements: Belt transmission causes less trouble and is less 
expensive than other forms of drive, because it is not seriously affected 
by a loss of alinement, which causes other transmissions to wear 
appreciably and frequently results in costly replacements. The 
flexible transmission insures minimum wear of the power plant, be¬ 
cause the elastic driving medium will transmit fewer road shocks than 



Fig. 193.—Showing Construction of Typical Idler Pulleys for 
Augmenting Tension of Driving Belts or Pedaling Chain. 


the positive form. This means that there is less wear on bearings and 
gears because of the slipping under abnormal loads, such as quick 
starting, rapid acceleration, etc. These same features also contribute 
materially to the comfort of the rider because of smooth action. It 
is the least complicated, and therefore it is the least liable to get out 
of order. The feature of silence is also commendable, as drive is by 
leather to metal contact instead of metal to metal connections. 

The application of flat, belt drive to one of the Harley-Davidson 
models is shown at Fig. 192. The method of operating the belt idler 
or jockey pulley on this machine is clearly shown at Fig. 193. The 
idler is carried at the end of a bell crank which has a segment of a 















342 


Motorcycles , Side Cars and Cyclecars 


gear as its other member. These gear teeth engage with suitable 
members formed at the lower portion of the operating handle. As 
the handle is pulled toward the rider, the idler pulley moves on an 
arc of a circle having a radius equal to the center distance between 
the idler pulley bearings and the pulley center. The flat belt may 
be normally loose when the idler is in the position shown, but when 
the pulley is raised to the position indicated by the dotted line the 



Fig. 194.—View of Power Plant and Drive of the Rudge-Multi Motor¬ 
cycle, Showing V Belt Transmission. 


belt is made to hug the engine pulley very closely, the effective arc 

of contact between the belt and the driving pulley is increased and 

a more effective drive obtained. The view at the right of Fig. 193 

shows one method of compensating for the variation in pedal sprocket 

centers as the rear wheel is moved to allow for belt stretch. A small 

% 

ball-bearing idler is mounted in a slotted support, and is moved down 
in the slot to tighten a loose chain, and moved up to loosen a tight 








Power Transmission System Parts 


343 


chain. Many of the belt drive machines still retain the pedaling 
chain, and suitable provision must be made to keep that member in 
proper adjustment. 

The V-belt drive which is used on the Rudge-Multi is shown at 
Fig. 194. The belt is a combination rubber and canvas form, and is 
utilized in conjunction with a variable pulley and friction clutch at¬ 
tached to the power plant. 

Types of Driving Belts. —The various forms of belts that have 
been applied for motorcycle propulsion are outlined at Fig. 195. That 
at A is a twisted, round rawhide belt that was the first form to be used 



Fig. 195.—Forms of Motorcycle Driving Belts. A—Twisted Raw- 
hide. B—Flat Leather Band. C—Duco-Flex Leather V Form. 

D—Shamrock Gloria, Rubber and Canvas Belt for V Pulleys. 

in motorcycle service. It had one advantage, and that was that its 
tension could be increased when desired by twisting the belt more 
closely together. A grave disadvantage was that it was materially 
affected by changes in weather, and was apt to stretch very much 
when wet, and shrink very fast when drying. This form was soon 
succeeded by the flat belt depicted at B, which is the same form that 
has been widely used for power transmission in our workshops. The 
V-belts were the next to receive general application. These may be 
divided into two main classes, one of which comprises all belts made 
of leather, while the other includes those made of other materials, 

























































344 


Motorcycles , Side Cars and Cyclecars 


such as canvas and rubber vulcanized together. A typical leather 
V-belt, the Duco-Flex is outlined at C, and a rubber belt, the 
Shamrock-Gloria is depicted at D. 

Various expedients are used by designers to secure flexible V-belts, 
as it is imperative that a belt bend easily in order that it may follow 
the contour of the small driving pulley attached to the engine crank¬ 
shaft. The special construction outlined at C involves the use of 
two continuous layers of leather to which are attached overlapping 
pieces that are to form the third and fourth plies of the belt. In the 
moulded rubber and canvas forms, shown at D, notches are cut in 
the bottom of the belt at frequent intervals, which permit the belt to 
describe a curve of small radius when the spaces close in as indicated, 
due to the bending of the belt. 

The usual construction of a leather belt of the V-form is outlined 
at Fig. 196. The belt consists of two continuous plies of leather that 
are riveted together between leather blocks with tubular rivets. The 
leather block used on the bottom of the belt is not as long as that 
on the upper part, and this construction permits of considerable 
flexibility. The Wata-Wata, an English belt, is shown at Fig. 197. 
In this construction, the upper and lower plies of the belt are sepa¬ 
rated by spacer blocks of arch formation, which allow the belt to bend 
around a circle of small radius because the lower portion or ply of 
the belt will fill the space between the blocks and permit the belt to 
bend easily. The ends of V-belts are fastened together by metal hook 
members which are made in a large variety of forms, one of which is 
shown in this illustration. 

Another English belt which is a distinctive construction, and which 
is said to give very satisfactory service, is shown at Fig. 198. This 
is known as the Whittle belt, and is a composite structure made of 
steel links carrying suitable bearing pins spaced between leather links. 
The two leather links are fastened together by a short regular pattern 
wood screw as indicated. 

Some of the forms of belt fasteners that have received a ready 
market are shown at Fig. 199. That at A is a simple form consisting 
of a pair of hinges having downwardly extending prongs to grip the 
belt, joined together by a simple hook member. The form at B uses 
a quick detachable hook which permits of some adjustment by using 


Power Transmission System Parts 


345 


hooks of different lengths. The form at C consists of a link of roller 
chain joining two simple duplicate V-shaped members carrying the 
screws for attachment to the belt. The wire hook depicted at D is 
the form of connector used with twisted rawhide belt. Another type 
of connector which provides some opportunity for adjustment is 
shown at E. When the belt stretches, the connecting member may 
be used to shorten the belt by changing its position. Instead of bear¬ 
ing at the extreme end one of the connecting members may be brought 



Fig. 196.—Typical Leather V Belt and Connecting Links. 


nearer the other by placing it in the bearing at the upper portion of 
the connector ring. 

b Various tools are necessary to maintain belt efficiency. One of 
these, which is shown at A, Fig. 200, is employed to cut belting of 
the V-form smoothly and accurately. It consists of a suitable casting 
member carrying a sliding cutting knife guided by slots in the casing, 
which is forced down to sever the belt by a set screw bearing against 
the back of the cutting blade. The other set screw is utilized to clamp 





































346 


Motorcycles , Side Cars and Cyclecars 


the belt tightly against the movable lower plate which may be raised 
when desired to accommodate smaller sizes of belts. Practically all 
of the connectors used with V-belts require that holes be made in 
the belts to permit of passing the screw that clamps the connector 
to the belt through it. A punch for making these holes is shown at 
Fig. 200, B. This is a double member, and the thumb-screw to which 
the punch is attached may be placed at either end. When in the 
position shown it will punch one-inch belt, and if the screw is reversed, 



Fig. 197.—Showing Construction the Wata-Wata V Belt. 


the device can be used for piercing seven-eighths-inch V-belt. After 
a belt has been shortened a number of times, a point will be reached 
where the ends will be too far apart to receive a standard connector 
of the simple form. In such cases, the links shown at C may be used 
to advantage because the center of the connector is composed of a 
block of rubber beveled off at the same angle as the V-belt. This 
grips the pulley and prevents slipping or noisy action which would 
be apt to result if a connector of the simpler form was used. 


















































Power Transmission System Parts 


347 


Standard Belts. —The regular pattern V-belt is made to run on 
pulleys that have the driving faces beveled so that the included angle 
between the flanges is 28 degrees. If trouble is experienced with 
slipping of a V-belt and the substitution of a new member for the 
old one does not cure the trouble, a gauge may be made of sheet metal 
and used as indicated at Fig. 201. If the pulley flanges are hollowed 
out, which would be apt to result after the pulleys have been in use 
for some time, this condition will be clearly indicated by the fit 
between the gauge and the flanges. Belts are made in a variety of 



Fig. 198.—Unconventional Form of V Driving Belt of Whittle Design, 
in Which a Combination of Leather and Steel Links are Used. 


widths, and are usually of special tannage because the ordinary oak- 
tanned leather used for belting in machine shops is absolutely un¬ 
suitable for the work demanded of a motorcycle drive. Chrome- 
tanned leather is generally used for belts because this produces a 
tough, sinewy material best adapted to resist oil, water and heat 
generated by excessive pulley friction. Chrome-tanned leather also 
has greater tensile strength than the oak-tanned and it will transmit 
more power. It is also more flexible, will not slip when wet, and is 



















































348 Molar cycle*. Side Cars and Cyclecars 

not apt to curl on the edges or stretch as much as the belting made 
by the other processes. 

Flat belts are usually made in two plies and will range from lj /2 to 
2 j /2 inches wide, the variations in size being by increments of one- 
eighth inch. Natural^, the greater the amount of power to be trans¬ 
mitted, the wider the belt must be to take the augmented pull. The 
plies are not only cemented together but, in some instances, they are 
also stitched at the edges. The cement used should be heat and 
water-proof, and it is also necessary to stretch the belts a number 



Fig. 199.—Various Forms of Connecting Links for Motorcycle Driving 

Belts. 


of times after cementing before the belt is ready for use, to give them 
an initial permanent set. 

In making V-belts, two continuous plies in the forms intended for 
medium-powered engines, and three continuous plies on the forms 
devised for larger power plants are cemented together, and then 
special two-ply blocks are riveted to the continuous plies with steel 
rivets to obtain the required depth of friction surface. The blocks 
are of special construction, in order to enable the belt to conform 
more readily to the small engine pulleys. All standard V-belts, 
whether made of rubber or leather have a 28 degree included angle. 

Belts vary in length from 7 to 1) feet, and the average length is about 
















Power Transmission System Parts 


340 


8 feet 6 inches. Leather belt is used almost exclusively in the United 
States, though the rubber and canvas V-belt is more popular abroad. 
The advantage of rubber belting is that it is not apt to be affected by 
water, but it is not as flexible as the leather belt, nor does it have the 
same amount of adhesion to the belt pulleys. Flat belt pulleys are 
usually made of cast iron covered with a layer of leather, or a lagging 



“ Stanley ” Spare Rlibber Link* 


Fig. 200.—Useful Appliances for Repairing Rubber and Canvas V Belt. 

of woven wire-asbestos fabric, in order to secure greater adhesion 
between the belt and pulley. Owing to the large amount of surface 
on the rear driving pulley, it is not customary to provide any lagging 
on that member, as sufficient adhesion is obtained without it. 

Lagging is not necessary on V-belt pulleys, because the tendency 
of the belt is to wedge itself in the space between the flanges, and as 




















350 


Motorcycles , Side Cars and Cyclecars 


the power developed by the engine increases, the adhesion augments 
proportionately because of a greater wedging effect. The four-ply 
V-belts vary in width from 54 inch to 1J4 inches by increments of 
one-eighth inch, and the five-ply belt, which is intended for use with 
powerful twin motors will vary from l)/g inches to V /2 inches in width. 
There is no intermediate size between 1J4 inches and 1J4 inches V- 
belt. The width of a V-belt is always measured at the top. 

The writer has made a careful ana^sis of belt drive machines pro¬ 
duced by American manufacturers for several years, in order to arrive 
at the average practice as relates to the sizes of belts used with various 
motor horse-powers. The following tabulation may prove useful for 
reference: 


Single Cylinders, up to 234 horse-power (Old Style Machines): 

Flat Belt.1J4 to 134 inches wide 

Twisted Rawhide. % to J4 inch dia. 

V-Belt. 54 to J4 inch wide 

Single Cylinders, 2J4 to 5 horse-power: 

Flat Belt, 2-ply.134 1/4 inches wide 

V-Belt, 4-ply. 74 to 1 inch wide 

Two Cylinder, up to 7 horse-power: 

Flat Belt, 2-ply .154 to 154 inches wide 

V-Belt, 4-ply. p .1 to 1J4 inches wide 

Two Cylinder, up to 9 horse-power: 

Flat Belt, 3-ply.1% to 2J4 inches wide 

V-Belt, 5-ply.1J4 to 1)4 inches wide 


Advantages of Drive by Chains.—The credit of being pioneers in 
the application of chain drive on motorcycles belongs to the Hendee 
Manufacturing Company in this country, and to Messrs Phelon & 
Moore in England. It was adopted by both of these makers on 
standard stock products in the year 1900, and both have been un¬ 
usually loyal and have consistently advocated chain drive ever since. 
Other makers followed their example, but they either did not realize 
that in order to enjoy the real benefit given by the chains that the 
machine must be especially designed for them or else the majority 
of motorcycle engines in those days were not as smooth-running as 
the creations of to-day, because for a time, the chain transmission 











Power Transmission System Parts 351 

was not generally favored on account of the alleged harshness of the 
drive. 

Other influences, however, were at work, and the consequent im¬ 
provement and increase of power in the engine, and the use of side 
cars, showed that the belt drive was not always adequate for powerful 
motors pulling heavy loads unless made of excessively large size. 
Various cushioning devices were also evolved in order to relieve the 
mechanism of the shock, due to positive transmission of power and a 
review of current practice indicates that chain drive is standard on 

most of the best-known 
American machines, and 
is generally accepted as 
producing a moderately 
silent, smooth-acting and 
reliable transmission. In 
Europe, the belt is still 
the most popular form 
o f power transmission, 
but indications point to 
a gradually increasing 
appreciation of chain 
drive in both England 
and France. 

There has never been 
any question regarding 
the positiveness and effi¬ 
ciency of chain transmis¬ 
sion. In fact, the first 
objections advanced against it was that it erred in being too positive. 
The early forms of motorcycle engines, especially the big single 
cylinder power plants did not deliver a very even turning moment as 
the power was applied as a series of violent shocks. As previously 
stated, the belt equalized the drive to some extent by slipping and 
stretching while the chain, as originally applied, transmitted the 
shocks to the machine, and thus not only caused considerable wear 
on the tires but promoted the discomfort of the rider. The introduc¬ 
tion of better balanced engines and more especially of various com- 



Fig. 201.—Defining the Application of a 
3 Gauge for Testing Accuracy of Flanges 
of V Belt Pulleys. 














352 


Motorcycles , Side Oars and Cyclecars 


pensating clutches and cushioning devices of one sort or another pro¬ 
moted the genera] adoption of chain drive. 

An important advantage of chains is that these do not need to be 
tight to transmit power, which is absolutely necessary in connection 
with the use of belts, especially the flat belt. In order to reduce belt 
slip, it is necessary that they be tight, and the belt pull causes con¬ 
siderable unnecessary friction on the engine bearings, especially of 
the plain type. With the chain, no initial tension is necessary, and 
the frictional loss due to high bearing pressures is not as large as 
with a tight belt. 



Fig. 202.—Side View of the Eagle Motorcycle Employing Single 

Chain Drive. 


In order to use the chains successfully, the conditions under which 
they work to the best advantage must be fully realized. The removal 
of belt pulleys and the substitution of sprockets, and the use of a 
chain instead of a belt, does not mean that satisfactory chain drive 
will be obtained. On the contrary, essential conditions peculiar to 
chain drive must be properly taken into account. First, the nature 
of the load must be understood. The action of the four-cycle internal 
combustion engine consists of a series of power strokes due to the 
explosion of gases which are interposed between periods of neutral or 
even negative effort While the explosion forces the piston violently 
downward, during the other three strokes and especially on the com- 





Power Transmission System Parts 353 

pression stroke, the resistance is exactly reversed. A load of this 
nature is generally known as “impulsive,” and is much more severe 
on the transmission system than the regular turning moment of an 
electric motor or the smooth action of a four-cylinder gasoline power 
plant. Consequently, if the chain drive is to be a thorough success, 
the shocks due to uneven power application must be reduced or ab¬ 
sorbed as far as possible by some cushioning mechanism. Another 
thing that must be taken into consideration is that the speed of a 
motorcycle engine is very high, and, consequently, the chain speed 
is correspondingly fast. This is especially true of the first reduction 
or countershaft drive chain. 

It is not generally realized that chain must travel at a velocity of 
1,500 to 3,000 feet per minute, and that the impact between the 
rollers of the chain and the teeth of the sprockets is very severe and 
frequent. It is therefore important that the chains be kept thor¬ 
oughly lubricated so the blows on the rollers may be softened by the 
interposition of a film of lubricant both on the outside of the roller— 
which is best attained by the use of an oil-bath gear case—and in the 
bush and rivet bearings. That the roller should be free to turn is 
also most important, since the wear is thereby distributed. 

In view of this last consideration, it is very necessary to make sure 
that the sprockets are in perfect alinement. Otherwise, the teeth cut 
into the side plates of the chain, on which they wear a shoulder or 
ridge, which often causes the rollers to stick, with the result that the 
impact on the roller always comes in the same place, tending to 
break it. Correct adjustment also is of course necessary, as, if the 
chain is too slack, it tends to mount the wheel teeth and also “whips,” 
which may have the effect of breaking the rollers, and in any case, 
intensifies the wear. The provision of a gear case, or at least some 
form of chain-guard, is highly desirable. Mud is not a satisfactory 
lubricant, and it is hopeless to expect the best results from a chain 
which is coated inside and out with slush and grit. The natural result 
is stiff joints, broken rollers, and rapid wear. 

A point to be looked to in designing a drive is that the number of 
links in the chain from engine to countershaft should not be an even 
multiple of the number of teeth in the engine-shaft sprocket, as if 
this is the case the force of the explosion comes more often on certain 


354 


Motorcycles , Side Cars and Cyclecars 


rollers than on the rest. To sum up, the three essentials to be looked 
for in a motorcycle drive are: First, some species of slipping or 
cushioning device; second, efficient and thorough lubrication, and 
third, a reasonable chain speed. 

On this last point, a compromise has to be aimed at. The chain 
speed may be reduced by reducing the diameter of the sprockets, i. e., 
the number of teeth. But, other things being equal, a small sprocket 
is more severe on the chain than a larger one, owing to the increased 
angle at which the wheel meets the chain. Normally speaking, the 
best results will be attained with driver or engine-shaft sprockets 
having from 15 to 17 teeth. 

Single Chain Drive .—The simplest form of chain transmission 
and the most efficient is the single chain drive which, to date, has not 
been extensively applied in motorcycle practice. The method of 
using a single chain is clearly outlined at Fig. 202. This involves the 
use of an engine-shaft clutch, which also acts as a cushioning device, 
from which the drive is to a large sprocket mounted on the rear 
wheel hub. In the machine shown, the rear sprocket has 64 teeth 
and the engine sprocket from 16 to 18 teeth. The system of trans¬ 
mission is efficient, and about the only disadvantage that can be ad¬ 
vanced against it is that the chain must be kept tight, because if 
loose it will be apt to flap or whip, owing to its length. 

Another method of using a single chain is in combination with an 
undergeared drive and is outlined at Fig. 203. In this, the first re¬ 
duction is by a spur pinion attached to the engine crankshaft which 
meshes with an internal gear that turns the driving sprocket. As 
practically all of the reduction in speed may be obtained between the 
gears, the front sprocket may be made nearly as large as the rear one, 
and the chain is operating under very favorable conditions, as relates 
to both chain speed and bending. The single-chain direct drive is, 
of course, the most efficient, as there is no bearing friction other than 
that of the engine shaft and rear hub to be overcome, while in the 
countershaft form its bearings consume power. 

Double=Chain Drive. —The method of employing two chains for 
driving, used on the Alcyon (French) motorcycle, is shown at Fig. 
204. A small sprocket is attached to a cushioning device carried on 
the engine shaft, and drives a larger sprocket mounted on a counter- 


Power Transmission System Parts 


355 


shaft of the simple form. The drive to the rear wheel is from the small 
countershaft sprocket to a large member attached to the rear hubs. 
This provides a double reduction system, there being one reduction 
in speed between the engine sprocket and the member it drives on 
the countershaft, and another reduction between the smaller sprocket 
on the countershaft and the larger member on the hub. The original 
and as time has proven, the most practical system of double-chain 
transmission is illustrated at Fig. 205, which shows the transmission 
method employed on the Indian motorcycle. Even on the earliest 
forms, a compensating sprocket or cushioning arrangement was used 



Fig. 203.—Undergeared Single Chain Drive of Reading-Standard 

Motorcycle. 


on the countershaft, but in the modern types it is, of course, un¬ 
necessary to use any cushioning device other than the free engine 
clutch regularly provided on all these machines. 

Types of Driving Chains. —The form of driving chain generally 
used at the present time for power transmission on both motorcycles 
and automobiles is a radical departure from the type of chain first 
used for the purpose. In order to reduce friction, and to insure easy 
running, rollers are used to come in contact with the sprocket teeth, 
and these roll instead of rub against the teeth as was the case with 
the block chain. A typical roller chain is shown at Fig. 206, A. 
Each roller is mounted on a bushing which joins a pair of side plates. 















356 Motorcycles , Side Cars and Cyclecars 

In this form, a link member is composed of two side plates, two bush¬ 
ings to hold them together, and two rolls that revolve on these bush¬ 
ings or hollow rivets. Each of these link assemblies is joined with 
its neighboring one by a simpler element composed of a pair of side 
plates and two solid rivets or bolts. The block chain which is shown 
at C is a simpler construction than the roller chain, as a link assembly 
is of the more simple form, i. e., two side plates and their retaining 
rivets is used to join the blocks. That shown at B is a roller chain 



Fig. 204.—Application of Double Chain Drive to Alcyon (French) 

Motorcycle. 

that can be used on block-chain sprockets. Block chains are seldom 
used for transmitting power at the present time, and when utilized 
are employed only for joining the pedaling sprocket to the corre¬ 
sponding member on the rear hub, or in connection with a step starter. 

The parts of a typical roller chain are clearly shown at Fig. 207. 
At A, a connecting link which is used for repair purposes or to permit 
of taking the chain apart when it is necessary to remove it is shown. 
At B, the connecting link employed to join the roller link members C 




Power Transmission System Parts 


357 


is outlined. The offset link at D is used in joining a chain together 
under conditions where the regular connecting link A cannot be em¬ 
ployed, which is the case if the chain has an uneven number of links, 
such as 63, etc. At the lower portion of Fig. 207, the chain repair 
tool used for taking riveted chains apart is shown. It consists of a 
block member which supports a slotted piece having the slots sepa¬ 
rated by a distance equal to the pitch of the chain to be repaired. 
A guide member shown at the right can be placed over the head of 
the rivet which is driven out by means of the punch that is adapted 



Fig. 205.—Double Chain Drive System Used on Indian Motorcycles 
on Which Machine This System of Power Transmission 
Originated. 


to fit the guide piece. This arrangement is the only practical method 
of holding a chain for repairing, as it not only insures that the rollers 
or links will not be marred but it also provides the firm support that 
is necessary to drive out the rivets. 

| The popular motorcycle chain used in this country is a ^g-inch 
pitch with a I^-inch width roll for engines below 5 horse-power, and 
5^-ineh pitch with T Vinch or ^g-inch roll for engines of greater 
power. Two other sizes of chains are being used to some extent, 
these being j^-inch and %-inch pitch. The pitch of a chain is the 










358 


Motorcycles , Side Cars and Cyclecars 


distance between the center of one tooth space to the center of the 
neighboring one. In some cases where very low-powered engines are 
used, chains of 3^-inch pitch with x 3 6 -inch or l^-inch wide rolls are 
sometimes*employed. The breaking strain of chains used will range 
from 2,000 pounds to 3,000 pounds. Considerable useful information, 
in the form of formulae for figuring chain length, sprocket sizes, etc., 
that will be of value to the designer or draftsman, or to the motor- 



Fig. 206.—Types of Motorcycle Driving Chains. 

cyclist who is mechanically inclined, are given in Figs. 208 to 210, 
inclusive 

Combination Chain and Belt Drive.— In an endeavor to obtain 
the advantages of both of the main systems of power transmission 
without the attendant disadvantages incidental to the use of either 
alone, combination drives are receiving considerable attention at the 
present time. The average composite drive consists of a chain or 
















Power Transmission System Parts 


359 


gear drive to a belt pulley, and from that member to a larger belt 
pulley on the rear wheel. The construction of the usual undergeared 
drive may be clearly grasped by referring to Fig. 211. While in this 
case the drive to the rear wheel is by chain, it is not difficult to sub¬ 
stitute a belt pulley for the sprocket and drive by the more flexible 
means. The first reduction is obtained by the spur driving pinion 
attached to the engine crankshaft which meshes with an internal or 
ring gear mounted in a suitable extension from the engine base and 
revolving on ball bearings of generous proportions. The ring gear 
carries the final drive member. 



Connecting Link 



</r; 


Rivet Punch 


Punch 

Guide 


OFset Link 
Link Support 


Fig. 207.—Roller Driving Chain Parts and Repair Tools. 
























3G0 


Motorcycles , Side Cars and Cyclecars 


For Calculating Length of Chain 


--A 



(All Dimensions in Inches.) 


D= Distance between centers. 

A = Distance between limit of contact. 

R~ Pitch radius of large sprocket. 
r= Pitch radius of small Sprocket. 

N = Number of teeth on large sprocket. 
n = Number of teeth on small sprocket. 

P = Pitch of chain and sprocket. 

(180°+2a) = Angle of contact — large sprocket. 

(180°—2a) = Angle of contact — small sprocket. 

R-r 

D 

A — I) Cos a 

Total length of chain. 

180-2a 

1 ---— n P -f- 2D Cos a. 


a = sin— 1 


180 +2a 

L = — i - -N P 


360 


360 


Fig. 208.—Useful Formulae for Obtaining Length of Driving Chain. 



















Power Transmission System Parts 


361 


One of the disadvantages incidental to belt drive when used alone 
was that a small driving pulley which did not provide a sufficiently 
large contact surface had to be used on the engine shaft to secure the 
proper gear ratio. With the undergeared drive, which is shown at 
the top of Fig. 212, or with the combined chain and belt drive out¬ 
lined at the bottom of the same illustration, it is possible to use a 
belt pulley of large diameter and obtain an arc of contact that will 


Minimum Centres for Chain Wheels 

Roller Drive 



When ratio is as I in. is to (3in.d- y + J4in.) or over, then centres = D-d. 
When ratio is less than lin. is to (3in. + -y 4-ysin.) then centres ° - f g +F 

DATA: 

P . . . Pitch of chain wheel in inches. 

D . . . Pitch dia. of chain wheel in inches, 
d . . . Pitch dia. of pinion wheel in inches. 


Fig. 209.—Diagram Showing Calculation for Minimum Centre Dis¬ 
tances for Sprockets. 

insure positive drive and minimum flexure of the drive belt. The 
first reduction is obtained by positive means which are best adapted 
for this purpose, while the final drive is taken by the flexible member 
which provides the smooth and yielding transmission that is so desir- 
able to relieve the power plant of road shocks. The view at Fig. 213 
is that of a representative American motorcycle, the Reading Stand- 











362 


Motorcycles , Side Cars and Cyclecars 


For Calculating Diameters of Sprocket Wheels for Roller 

and Built-Up Block Chains 


N = Number of teeth in sprocket. 
P = Pitch of chain. 

D = Diameter of roller. 

180° 


Pitch Dia.=- 

Sin. a 

Outside Diameter = Pitch -j- D. 
Bottom Diameter —Pitch — D. 



For Calculating Diameters of Sprocket Wheels for Block 
Center and Twin-Roller Chains 



N = Number of teeth. 


b = Diameter of round part of 
chain block (usually .325) 
B = Center to center of holes 
in chain block (usually.4) 
A = Center to center of holes 
in side links (usually .6)- 


a 


180® 

~N~ 


Tan. B = 


Sin. a 


B 


+ Cos a. 


Pitch Diam. 


A 

Sin. B 


Outside Dia. = Pitch Dia.-(-A 

Bottom Dia. = Pitch Dia. — b 

> 

In calculating the diameter 
of Sprocket wheels, the bottom 
diameter is the most important 



Fig. 210.—Diagrams Showing Method ot Calculating Sprocket Sizes 

for Roller and Block Chains, 
























Power Transmission System Parts 


363 



Gear Case 


Fig. 211.—Undergeared Drive of Thor Design. 

ard, employing the combination undergeared drive. The relative 
size of the front and rear driving pulleys may be readily ascertained 
and it is not difficult to understand how a combination drive of this 
nature is destined to become a very popular system, inasmuch as it 
will provide a positive drive and yet a flexible one. 










364 Motorcycles , Side Cars and Cy decars 

Bevel and Worm Gear Final Drive. —The most popular system 
of driving automobiles is undeniably that in which thoroughly en¬ 
cased gearing is used. The problem of applying this form of gearing 
to motorcycles is not an easy one to solve, because the construction 
is difficult to apply. In an automobile, it is not necessary to remove 




Fig. 212.—Two Methods of Using Belt Transmission in Connection 
With Positive First Reduction Means. 















































































365 


Power Transmission System Parts 

the rear axle every time a wheel must be reached to make repairs on 
the tires. In a motorcycle, it is necessary to take the rear wheel out 
of the frame before one can change a shoe or one-piece inner tube, and, 
whenever gear drive is used, it is somewhat of a job for an amateur to 



Fig. 213.—Three-Quarter Front View of 1914 Reading-Standard Single 
Cylinder Model, Showing Application of Undergeared V Belt 
Drive. 


remove the wheel, and more of a proposition to replace it and secure 
proper adjustment of the drive gearing. 

A bevel gear drive which has received successful application on the 
Pierce four-cylinder motorcycle is shown at Fig. 214. The rear hub 
member carries a bevel gear in place of the usual drive sprocket, and 
the power is transmitted to that member by a bevel drive pinion 








Motorcycles , Side Cars and Cyclecars 


306 

securely attached to a drive shaft that extends to the motor crank¬ 
shaft. A worm gear drive used on an English motorcycle is shown at 
Fig. 215. The system is just the same as that previously described 
except that worm gearing is used instead of the bevel, for with either 
of these forms it is necessary to mount the engine in the frame in such 
a way that the crankshaft is parallel to the top frame tube. 



Fig. 214.—Bevel Gear Driving System of Pierce Four Cylinder 

Motorcycle. 


The power transmission of the Fielbach motorcycle at Fig. 216 is 
distinctive, inasmuch as the twin-cylinder power plant is mounted in 
the frame in the conventional manner with its crankshaft at right 
angles to the frame tubes. The drive is by spiral gearing at the engine 
through a cone clutch and sliding gear transmission of the two-speed 
type to a worm gear carried on the rear axle. The view at the top 





































































































367 


Power Transmission System Parts 


shows the relation of the engine gearing, the clutch and the change- 
speed gearset. The drive from the gearset-driven shaft is to a worm 
mounted in a suitable casing which is shown in the longitudinal sec¬ 
tion in the lower left hand corner. The method of fastening the worm 
gear to the wheel hub is clearly outlined in the right hand corner. 
This system of gearing is more complicated and much more expensive 
to construct than the simpler two-chain or combination chain and 


i 





DHvir^5 Worm 


ear - 

Case 





Fig. 215.—Worm Drive System of T. A. C. (English) Four Cylinder 

Motorcycle. 


belt drive, but it has the important advantage of having all the driving 
elements thoroughly encased and protected from the abrasive effect 
of road grit, which cannot be said of any of the chain or belt drive 
systems. An important advantage of the positive encased gear drive 
is that the housings in which the gears are mounted may be filled with 
lubricant, and this not only cushions and silences the drive but it 
also reduces friction and wear, and promotes long life of the driving 







368 


Motorcycles, Side Cars and Cyclecars 



Fig. 216.—Application of Worm Drive System on the Fielbach Motorcycle. 










































































































































































































Power Transmission System Parts 309 

Relation of Engine Power to Gear Ratio.— In one of the earlier 
chapters the reason for supplying various gear ratios has been con¬ 
sidered in some detail, and the importance of selecting that best 
adapted so the power of the engine will be delivered most effectively 
is an important phase of motorcycle design. An engine may be geared 
too high, which means that it will have some difficulty in overcoming 
the resistance imposed by hills or bad roads but is very fast on the 
level. If a machine is geared too low, it will be a good hill climber 
but will not operate at satisfactory speeds under good conditions un¬ 
less the engine is run excessively fast, which would produce more 
rapid depreciation of the power plant. 

The two tables appended are given to show the gear ratios recom¬ 
mended by engine builders for their different motor types. It is, of 
course, understood that the designer of the motorcycle will select the 
power plant of the proper capacity for the machine to which it is fitted. 
The first table is given by the makers of the Precision (English) 
engines, various models of which have been illustrated in this work. 
The last table is especially valuable, as it shows not only the gear 
ratios but the road speeds obtained with various sprocket sizes and 
single and twin engines. This table has been compiled by the F. W. 
Spacke Machine Company who make the De Luxe motors. Other 
tables and formulae to assist in figuring speed are also presented. 

Riders will do well to remember that cycle engines are essentially 
high-speed engines, and should not be over-geared. The following 
table will be found to give best results both from the point of view of 
flexibility and average speed: 


Engine Type. 

Gear Ratio for Solo 
Riding. 

Gear Ratio for 
Sidecars, Top Gear. 

► 

2 24 horse-power . 

524 to 1 


2 24 horse-power . 

5 to 1 


324 horse-power. 

424 to i 

514 to 1 

324 overhead valves. 

4 to 1 

5 to 1 

4 horse-power twin.. 

4 24 to l 

5 to 1 

Green model. 

4 to 1 

5 to 1 

4 24 horse-power. 

424 to l 

5 to 1 

6 and 8 horse-power twin models. . . 

4 to 1 

4 24 to l 





















370 Motorcycles , Side Cars and Cyclecars 


TABLE OF SPROCKET SIZES, GEAR RATIOS AND MOTORCYCLE 
SPEEDS FOR USE WITH DE LUXE ENGINES. 


Size of Motor. 

Motor 
Sprocket 
N umber 
Teeth. 

Eclipse 

Countershaft 

Sprockets. 

Hub 

Sprocket 

Number 

Teeth. 

Gear 

Ratio. 

Speed with Motor 
Running 2,500 R.P.M. 
Miles per Hour. 


12 

33 and 17 

27 

4.37 to 1 

47.7 

4 and 5 

12 

33 and 17 

29 

4.69 to 1 

44.4 

horse-power 

12 

33 and 17 

31 

5.01 to 1 

41.5 

singles 

12 

33 and 17 . 

35 

5.66 to 1 

36.8 


14 

33 and 17 

23 

3.19 to 1 

65.3 

7 and 9 

14 

33 and 17 

25 

3.47 to 1 

60.1 

horse-power 

14 

33 and 17 

27 

3.75 to 1 

55.6 

twins 

14 

33 and 17 

29 

4.02 to 1 

51.8 


14 

33 and 17 

31 

4.30 to 1 

48.4 


The point of highest efficiency and horse-power development is 
represented at approximately 2,500 revolutions per minute, on stand¬ 
ard stock motors, and is, for that reason, taken as a basis for estimat¬ 
ing gear ratios. The above does not, therefore, necessarily represent 
the extreme maximum of speed that may be obtained from any gear 
ratio. 

SPEED FORMULA. 

To reduce A miles in B seconds to miles per hour, 

. 3,600 

A X —r— = miles per hour. 

B 

SPEED EQUIVALENTS IN AMERICAN AND FRENCH 

MEASUREMENTS. 

1 mile per hour = 88 feet per minute. 

= 1.46 feet per second. 

= 27.8 meters per minute. 

= 0.463 meter per second. 

1 kilometer per hour = 0.624 miles per hour. 

= 54.9 feet per minute. 

= 0.914 meter per second. 























371 


Power Transmission System Parts 


RATE OF SPEED IN MILES PER HOUR FOR ELAPSED TIME OVER 
THE MEASURED MILE FROM ONE TO THREE MINUTES. 


Time Over 
Measured 
Mile. 

Rate of Speed 
in Miles per 
Hour. 

Time Over 
Measured 
Mile. 

Rate of Speed 
in Miles per 
Hour. 

Time Over 
Measured 
Mile. 

Rate of Speed 
in Miles per 
Hour. 

Min. 

Sec. 


Min. 

Sec. 


Min. 

Sec. 


1 

0 

60.00 

1 

27 

41.38 

1 

54 

31.58 

1 

1 

59.00 

1 

28 

40.91 

1 

55 

31.30 

1 

2 

58.06 

1 

29 

40.45 

1 

56 

31.03 

1 

3 

57.14 

1 

30 

40.00 

1 

57 

30.77 

1 

4 

56.25 

1 

31 

39.56 

1 

58 

30.50 

1 

5 

55.38 

1 

32 

39.13 

1 

59 

30.25 

1 

6 

54.54 

1 

33 

38.71 

2 

0 

30.00 

1 

7 

53.73 

1 

34 

38.29 

2 

3 

29.26 

1 

8 

52.94 

1 

35 

37.89 

2 

6 

28.57 

1 

9 

52.17 

1 

36 

37.50 

2 

9 

27.90 

1 

10 

51.42 

1 

37 

37.11 

2 

12 

27.27 

1 

11 

50.70 

1 

38 

36.73 

2 

15 

26.66 

1 

12 

50.00 

1 

39 

36.36 

2 

18 

26.08 

1 

13 

49.31 

1 

40 

36.00 

2 

21 

25.53 

1 

14 

48.65 

1 

41 

35.64 

2 

24 

25.00 

1 

15 

48.00 

1 

42 

35.29 

2 

27 

24.49 

1 

16 

47.37 

1 

43 

34.95 

2 

30 

24.00 

1 

17 

46.75 

1 

44 

34.61 

2 

33 

23.53 

1 

18 

46.15 

1 

45 

34.28 

2 

36 

23.07 

1 

19 

45.57 

1 

46 

33.96 

2 

39 

22.64 

1 

20 

45.00 

1 

47 

33.64 

2 

42 

22.22 

1 

21 

44.44 

1 

48 

33.33 

2 

45 

21.81 

1 

22 

43.90 

1 

49 

33.03 

2 

48 

21.42 

1 

23 

43.37 

1 

50 

32.72 

2 

51 

21.05 

1 

24 

42.85 

1 

51 

32.43 

2 

54 

20.69 

1 

25 

42.35 

1 

52 

32.14 

3 

0 

20.00 

1 

26 

41.86 

1 

53 

31.86 

• • 

• • 










































CHAPTER VI. 


DESIGN AND CONSTRUCTION OF FRAME PARTS. 


The Motorcycle Frame Structure—Foot-Boards—Rear Wheel Stands— 
Spring Forks—Spring Supported Seat-Posts—Spring Frames—Saddles 
and Tandem Attachments—Coasting and Braking Hubs, Why Used— 
Requirements of Pedal Drive Mechanism—What Brakes Should Do— 
Force Needed at Brake—Principle of Brake Action—Friction Co-efficient 
and Its Relation to Brake Design—Leading Types of Brakes—Operation 
of Typical Braking and Coasting Hub—How Rider’s Effort is Multiplied 
—Motorcycle Tires—Side Car Advantages—Forms of Side Cars—Side 
Car Attachment and Control—Methods of Starting Motorcycles— 
Indian Electric Starting and Lighting System—Motorcycle Control 
Methods—Bowden Wire Control. 

We have discussed at some length, in a previous chapter, the 
various forms of motorcycle frames and methods of power plant 
support in a general way. In view of the important functions of the 
frame structure, it may be well to describe this important component 
upon which the strength and endurance of the entire assembly de¬ 
pends more completely. A typical loop frame, such as used on the 
Indian motorcycle is shown at Fig. 217, and this shows clearly all of 
the parts, with the exception of the wheels and handle-bars that are 
generally considered as being part of the frame assembly. 

It will be observed that in certain essential respects this frame 
differs materially from those used in bicycle construction. The looped 
member that supports the motor, the drop at the seat-post mast, and 
the elimination of the usual diamond construction at the rear end are 
all radical departures from bicycle frame design. In this construction, 
the effort is made not only to suspend the weight of the rider by 
resilient members other than pneumatic tires but by the use of the 
laminated leaf spring fork and the distinctive double cradle spring 
rear construction, the entire weight of the power plant and its aux¬ 
iliaries as well as the rider are spring supported and protected from 

372 


Design and Construction of Frame Parts 373 

the undesirable influences of road shock. The complete frame as¬ 
sembly consists of the main frame member to which are attached the 
front fork at the steering head, a saddle over the seat-post tube, a 
luggage carrier, chain-guard, mud-guard, and suitable stand at the 
rear end. 

The frame shown at Fig. 218 is representative of the form of con¬ 
struction in which the motor base is depended on to join the open 
portion of the frame when the power plant is in place. The im¬ 
portant parts of this assembly are also clearly outlined. The frame 



Fig. 217.—Complete Frame Structure of Indian Motorcycle. 


at Fig. 219 is a loop design of merit, and shows the complete frame 
assembly minus the rear wheel. The motor supports are brazed to 
the frame loop and are in the form of brackets to which the lugs 
attached to the engine base are bolted. Attention is directed to the 
distinctive method of strengthening the rear end by means of vertical 
brace tubes that join the rear forks and rear-fork stays together. The 
form of the mud-guards, the design of the saddle and handle-bars, and 
the method of housing the tool compartment under the saddle, in the 
space between the seat-post mast and the rear mud-guards are also 
clearly depicted. Another open frame is shown at Fig. 220. This 
differs from that previously described, in that the motor casing is 


























374 


Motorcycles, Side Cars and Cyclecars 



Fig. 218.—Frame of 1912 Eagle Motorcycle Showing Opening Left When Power Plant is Removed. 










Design and Construction of Frame Parts 


375 


r 



Fig. 219.—The Emblem Loop Frame With Reinforced Rear Construction. 












376 


Motorcycles , Side Cars and Cyclecars 



secured to an extension of the crank-hanger by two bolts, and to the 
end of the diagonal tube with one bolt. Both of -these members are 
forked so it is a simple matter to remove the power plant from the 
frame when necessary. 

A motorcycle frame is generally built up of seamless steel tubing, 
though some designs have been evolved in which a portion of the frame 
is composed of a casting member to which the tubes were attached. 
The frames illustrated at Figs. 217 to 220 are of the pattern in which 
the various fittings are joined together by steel tubes. The Schickel 
frame which is depicted at Fig. 221 is a distinctive construction be- 


Fig. 220.—Frame of Excelsior Motorcycle Showing Motor Supports. 

cause the main portion of the frame is a large aluminum casting which 
serves as a fuel container. The steering head and a portion of the 
seat-post tube retaining member are formed integrally with it. An¬ 
other suitable projecting boss is employed to support the front 
diagonal tube. The rear fork assembly is built of tubing in the con¬ 
ventional manner. The Fierce motorcycle employs a frame made of 
large diameter tubing, which members also serve as fuel and oil con¬ 
tainers, and which provide a frame of exceptional strength though 
unconventional in appearance. 

When motorcycles were first made, light steel stamped reinforce- 













Design and Construction of Frame Parts 377 

ments of the form used in bicycle frame construction were widely 
employed to hold the various parts of the motorcycle frame together. 
At the present time, stampings have been discarded for more sub¬ 
stantial drop forgings and malleable iron castings. The steering head 
of practically all motorcycles is in the form of a forging or semi-steel 
casting provided with a substantial rib joining the two bosses to 
which the frame tubes are brazed. The seat-post cluster is also a 
forging and has four projecting bosses. One of these is intended to 
secure the seat-post tube, the one at the front is for attaching the 
upper frame member while the two at the rear form an anchorage for 



Fig. 221.—The Schickel Frame Construction. 

the rear-fork tubes. The crank-hanger is still another member which 
varies according to the design of the frame to which it is fitted. The 
two common methods of brazing the frame tubes employed differ in one 
essential. The fittings are joined to the tubing in some frames by 
being pushed in the interior of the tube. This makes what is known 
as a flush joint because no evidence of the point of juncture between 
the frame and the fitting is noticed. The steering head forging of 
the Indian motorcycle, which is shown at Fig. 222 has internal rein¬ 
forcement or flush joints, while the steering head fitting of the frame 
shown at Figs. 219 and 220 is attached by inserting the tube inside 
of projecting bosses that form part of the fitting. This method is 





SfWf;'’: 


mm ns 

jV v 


Hun^orced Tube, 

... ' 

Umforcement 


C L 

Dtterm< 


extension rrc 
Head Forging To WVuch 

Tube is 6raxed 


ein^oreement 


378 Motorcycles , Side Cars and Cycle cars 

often combined with an internal reinforcement and is said to be 
stronger, though not so neat in appearance, than the flush joint frame 
construction. The latter has survived from bicycle practice where it 
was desirable to eliminate all corners in which dirt or dust could 
collect, and also to have a smooth or finished appearance for the frame. 
In a motorcycle, the factor of strength is the most important con¬ 
sideration so that externally reinforced joints are used fully as much 
as the flush joint construction. The tubing used in motorcycle con¬ 
struction is not only of heavy gauge and of large diameter but is in¬ 
variably provided with an internal reinforcement which in most cases 
is a vertical steel piece running through the center of the tube. This 


Fig. 222.—Steering Head Construction of Indian Motorcycle, Showing 
Internal Reinforcement and Method of Obtaining Strength While 
Using the Flush Joint Construction. 








Design and Construction of Frame Parts 379 

reinforcement is shown at Fig. 222. Another reinforcement which is 
even stronger than the single vertical member that bisects the tube 
into two D-shape or semi-circular sections is in the form of a triangular 
tube securely attached to the interior of the round frame tube. This 
tubing is used on the Emblem motorcycle, and is shown at Fig. 223. 

The sizes of tubing used depends upon the character of the rein¬ 
forcement and the strength it is desired to obtain in the motorcycle 
frame structure, which, of course, depends largely on the size of the 
power plant installed. A frame that may appear light when viewed 
from the outside on account of using tubing of small diameter may 

actually be stronger and 
weigh more than a more 
substantial looking frame 
of large diameter tubing, 
because it would have 
thicker walls and perhaps 
a more substantial in¬ 
ternal brace member. 
The accepted method of 
fastening the frame com¬ 
ponents together is by a 
combination ot pinning 
and brazing. When the 
frame is first assembled, 
it is placed in an alining 
fixture which insures that 
all the tubes will fit the various fittings to which they are attached 
properly, and that the center line of all the tubes comprising the main 
portions of the frame coincide. The next operation is to fasten the 
members together by drilling holes through the tube, and fitting and 
driving steel pins through these to hold the members together so the 
frame may be handled during the brazing operation. This process con¬ 
sists of heating the portion of the frame where the joint is to be made 
to a considerably higher point than the melting point of the spelter 
employed in joining the parts. The frame tube and fittings are raised 
to just below a white heat, and the binding material, which is a brass 
alloy in a molten condition is poured in the minute open space between 



Fig. 223.—Tubing Used in Emblem Motor¬ 
cycle Frame Has Triangular Reinforce¬ 
ment. 




380 Motorcycles , Side Cars and Cyclecars 

the frame tube and fitting at the joint. A flux, consisting of borax, 
is mixed with the spelter so it will flow readily between the tube and 
projecting member to which it is attached. When the joint is allowed 
to cool, the two members are held together by a thin layer of brass 
which forms a very strong joint that will give absolutely no trouble 
if it has been properly made. 

There is also a tendency in modern motorcycle factories to use the 
oxy-acetylene flame in welding parts together, and this also makes 
a very strong joint. The process of electric butt welding or spot 
welding may also be used to advantage at various portions of the 
frame structure. Brazing is the method generally followed, because 
the process is well known and has been highly developed through 
many years of use in building bicycle frames. After the frame struc¬ 
ture has been permanently assembled and all its components are held 
firmly together, the alining fixture is again brought into play and 
the frame straightened by suitable clamps if it has been knocked out 
of proper alinement by distortion due to the heat it was subjected 
to during the brazing process. After this, the frames are thoroughly 
cleaned, and all of the protruding spelter or flux at the joints is chipped 
or filed off. The frame tubes are then polished and smoothed by 
rapidly moving emery-coated cloth belts preparatory to the applica¬ 
tion of the enamel. 

The size of the tubing employed averages about 1 J/g inches diam¬ 
eter for the seat-post mast and the diagonal tube extending from the 
steering head. The upper and lower frame members that join the 
steering head to the seat-post mast and between the seat-post mast 
are usually of 1-inch diameter tubing. The rear forks and rear fork 
stays will be of J^-inch or %-inch round tubing, though sometimes 
oval section tube may be employed for the rear forks. The front 
forks of most motorcj^cles are composed of oval section tubes which 
taper down from where it is brazed to the fork crown forging to the 
lower portion designed to carry the wheel hub, or the links to which 
that member is secured. Sometimes round tubing is used for front 
fork construction as shown at Fig. 218, though the general practice 
is to use the tapered section, flat oval tube. It is not considered good 
practice to use tubing much thinner than /j-inch wall, and for the 
most part, even when it is well reinforced, tubing with a 3^-inch 


Design and Construction of Frame Parts 


381 


thick wall is used for the principal frame members, such as the seat- 
post mast, the upper frame tube and the motor supporting loop 
member. 

Foot Boards. —There is a growing tendency on the part of motor¬ 
cycle designers, which has been fostered largely by the demands of 
the riders, to provide auxiliary foot-rests in addition to the usual 
pedals that have been used on motorcycles from the first. Foot-rests 
were first used on foreign machines, many of which have entirely dis¬ 
carded the pedaling cranks so widely used in this country. As these 
members are replaced by a simple starting crank or kick starter on 
motorcycles employing variable speed gears, it is necessary to provide 
some means for supporting the rider’s feet. Naturally the simplest 
way was to braze extentions to the frame tube or attach foot-pads 
to the power plant in some way. 

Some of the examples of foot supports used on American machines 
are shown in detail at Fig. 224. That at the top is the rigging used 
on the Excelsior motorcycle. The foot-rests are steel drop forgings 
of approximately the size of the average foot that are carried by a 
substantial auxiliary bracket member secured at its lower ends to 
one of the crank-case bolts and at its upper end to the diagonal frame 
tube by a substantial clip composed of two steel stampings held 
together by through bolts. The foot-rests are attached to suitable 
extensions by a hinge that permits of folding them up out of the way 
or to provide a safeguard against breaking them off or bending them, 
should the machine fall over. With the Excelsior assembly, a brake- 
operating pedal is included in order that the rider may work the brake 
as effectively when his feet are on the foot-rest as when they are on 
the pedal crank. The simple form shown in the lower left hand corner 
is used on the Schickel motorcycle, and consists of two simple cast 
aluminum members attached to a laminated leaf spring that is in¬ 
tended to provide a resilient support for the feet of the rider. The 
Iver-Johnson foot-rest also depicted at Fig. 224 is a folding type that 
offers a secure support for the rider’s feet. It is carried by two hinges 
from a stamped steel member anchored to the frame. 

In some machines, notably the Henderson and the two-speed 
Indian, the foot-boards are depended on entirely to support the feet 
of the rider, and no pedals are provided. There seems to be a ten- 


382 


Motorcycles , Side Cars and Cycle cars 


dency toward the elimination of the pedaling gear that has for so 
long been a feature of bicycles and motorcycles, and while it was 
formerly an essential part of the machine on the early types without 
two-speed gears or free engine clutches and equipped with power 
plants of low rating, it is no longer necessary to assist the motor up 



Fig. 224.—Examples of Foot Rest Construction Found on American 

Motorcycles. 


a hill by vigorous pedaling or to constantly restart the motor after 
stopping it in traffic. The free engine clutch makes it possible for the 
rider to control his machine, and to bring it to a stop without affecting 
the motor, and the variable speed gear makes it possible to overcome 
all adverse conditions by the power of the motor alone. For this 
reason there is some talk about the elimination of the pedaling gear, 











Design and Construction of Frame Parts 383 

and the substitution of foot-rests and suitable controlling levers that 
will permit of positive motorcycle control. There is considerable to 
be said in favor of the pedaling gear, however, and its value is clearly 
established in the mind of the rider who has tried to start a stiff 
motor on a cold day by a more or less positive kick starter which 
does not permit of spinning the motor, as is possible when the effort of 
the rider can be applied with both feet through a substantial chain 
and crank to the rear wheel of the machine, which in turn rotates the 
motor crankshaft very briskly through the driving gearing, and which 
induces an obstinate motor to start even when it is difficult to vaporize 
the gasoline. Another feature is that brisk pedaling produces a hot 
spark at the spark plug, because the current production from the 
magneto is of more value when that member is rotated briskly. While 
it is thoroughly practical to start a four-cylinder motor by a starting 
crank, it is conceded that it is more difficult to start a single cylinder 
to twin motor with a starting handle, unless conditions are favorable. 
The writer believes that the pedaling gear is a desirable fitting, be¬ 
cause it provides a means of supporting the rider's limbs when they 
become cramped from maintaining a constant position on the foot¬ 
rest. Pedals also permit of considerably more comfortable riding on 
rough roads than foot-rests do, because it is possible for the rider to 
relieve the saddle of his weight when running on rough ground by 
using the pedals for support. They are also valuable in providing 
a positive control of the braking and coasting hub which forms an 
essential part of many American motorcycles of modern design. 

Rear Wheel Stands. —The motorcyclist of to-day is fortunate in 
having many devices included as standard equipment on the motor¬ 
cycle he purchases, that had to be bought as an accessory or that 
could not be obtained at any price with the early machines. No 
motorcycle sold at the present time would be considered complete 
without an integral stand by which the rear wheel can be raised from 
the ground and the machine kept upright when left by the rider. It 
is not more than six years ago that the portable stand which is now 
considered indispensable was unknown. If it was necessary to stand 
the machine up, it had to be leaned against some wall or tree which 
did not always prove to be as secure a backing as the rider wished, 
because the machine might slip from its upright position, and when 


384 


Motorcycles , Side Cars and Cyclecars 



the rider returned to his mount he was just as apt to find it lying 
on its side as in the upright position that he left it in. If it was 
necessary to raise the rear wheel from the ground, as in changing a 
tire or in making adjustments to the brake or hub, considerable in¬ 
genuity was necessary to improvise a suitable support for the rear 

end from a couple of 
boxes, odds and ends of 
boards, or even piles of 
bricks. 

It is said that the first 
stand was offered by the 
Hendee Manufacturing 
Company for use in con¬ 
nection with the Indian 
motorcycles, during the 
early part of 1908. This 
consisted of two separate 
supporting members or 
legs fitted with clamps 
designed for attachment 
to the rear fork stays 
and hinged so the leg 
section could be folded 
up and away from the 
ground when the device 
was not in use. While 
this was a big improve¬ 
ment, it had the grave 
defect that it could not be used very well on soft ground, as the 
limited amount of contact at the lower portion of the legs would 
permit one or the other to settle into the earth, and either allow the 
machine to fall over or would permit the rear wheel tire to drag 
against the ground when the motorcycle was being tuned up on the 
stand. 

At the present time, the stands are made with a cross piece at the 
bottom, which not only serves as a reinforcement but which provides 
an added means of support on soft ground. A motorcycle stand must 


St and 


Fig. 225.—The Indian Rear Wheel Stand. 










Design and Construction of Frame Parts 385 


be light, strong and rigid. It must be applied so it can be swung into 
place easily and securely fastened out of the way when not in use. 
The stand at Fig. 225 is a tubular construction employed on the 
Indian motorcycle. It is hinged at its upper end to the slotted plate 
member or rear hub carrier at the point of intersection between the 
rear forks and rear fork stays. Two arms or projecting members of 
T section are brazed to the stand tubes, and are of such form that 


Fig. 226.—The Automatic Stand Used on Eagle Motorcycles. 

they will rest against suitable stops on the frame. The stand at 
Fig. 226 is that used on the Eagle, and is an automatic type. Instead 
of tubing, channel section steel with substantial bracing members 
and forged arms is employed. The arms have a fork end at their 
upper portion that rests against the frame tube when the stand is 
in its operative position. A pair of tension springs are provided to 
return the stand to the position it occupies when not in use, auto¬ 
matically as the motorcycle is pushed off of the stand. The springs 



■ 










380 


Motorcycles , Side Cars and Cycle cars 


\_I . j-* H 1 Antw 



Fig. 227.—The Yale Spring Fork Construction. 


draw the member into the stand retaining clip in the form of a piece 
of spring steel securely riveted to the lower portion of the rear mud 
guard. The front wheel stand which forms an item of equipment on 
many European machines and which has been previously illustrated 
is not supplied as a standard fitting on any of the American types, 
though some have been fitted to their machines by experienced riders 
familiar with the advantages obtained through its use. 

Spring Forks. —One of the first concessions made for the comfort 
of the rider was the application of a resilient support for the front end 
of the frame in order that the shock incidental to operation over rough 
roads would be taken by springs instead of transmitted directly to 
the handle bars of the machine. This jarring promoted fatigue be- 












Design and Construction of Frame Parts 387 

cause of the shocks the rider’s arms received. Even the earlier forms 
of saddles were comfortable, inasmuch as they were provided with 
fairly resilient springs or were well padded, so the attention of the 
designer was directed first to spring fork development on account of 

the complaints of the 
riders of the vibration at 
the handle bars. Spring 
forks have been made in 
infinite variety, though 
the object of all design¬ 
ers is to obtain the re¬ 
silient feature without 
sacrificing strength 
unduly. 

Two types of springs 
have been utilized to take 
the shock imposed on the 
front wheels. When coil 
springs are employed 
they are usually housed 
in casings of tubular 
form, though with leaf 
springs the resilient mem¬ 
ber is necessarily exposed. 
The fork used on the Yale 
motorcycle is shown at 
Fig. 227. It consists of 
two members, a fixed fork 
attached to the steering 
head in the usual way, 
and a movable fork. 
An extension piece carried from the fixed fork is mounted be¬ 
tween springs at the upper end of the movable member, while the 
lower portion is attached at the center of the hub carrying link 
members. These are attached to the wheel hubs at one end and 
fulcrum on suitable bearing studs attached to the fixed fork end at 
the other. When the wheel encounters an obstacle, the hub carrying 


W&i 




K. 


jfeFixed Spring C&se 

Enclosed Shock 
Absorbing Mid RatoiV 

Check SprmcSs 
•» ° 

CAavahie Spring 
Case 



tAovable Fork 


Fig. 223.—Sectional View of the Spring Case 
of Reading-Standard Spring Forks, 
Showing Load Carrying and Recoil 
Check Springs. 






388 Motorcycles , Side Cars and Cyclecars 

link will move on the supporting bearing, and will force the movable 
member upward. This motion is resisted by the extension forming 
part of the fixed fork and by a spring carried below the extension in 
the upper portion of the movable fork tube. Another spring is 
mounted above the extension in order to prevent rapid rebound. The 
sectional view of the spring fork used on the Reading-Standard shown 
at Fig. 228 shows another application of the spiral spring principle. 
The movable fork member is attached to the hub carrying links in 
the same manner as previously described, and carries two spring 
members inside of a movable spring case which is guided by a fixed 
spring case attached to the upper portion of the steering head. The 
shock absorbing and recoil check springs are clearly shown and both 
are thoroughly encased and protected inside of the spring casing. 

The application of the laminated spring to secure resilient wheel 
support was first tried out on the Marsh-Metz motorcycles, and has 
been retained on the modern product manufactured by these interests 
which is known as the “Eagle” motorcycle. This construction is 
clearly shown at Fig. 229. The front hub is carried by links which 
fulcrum on suitable bearings at the end of the fixed fork assembly. 
Attached to the plate that takes the place of the usual fork crown 
is a six leaf spring, and from the eye at the forward end of this 
member a movable fork member composed of two steel rods passes 
to the front hub carrier. As the wheel is moved by irregularities on 
the road surface, it is apparent that the leaf spring will be raised and 
that the shock will be absorbed in this manner. 

The cradle spring fork which is an important feature of design on 
the Indian motorcycles is shown at Fig. 230. The advantages claimed 
for this type of spring include maximum flexibility, which is said to 
be produced by the curved end of the lower leaves, and the quick 
dampening of the oscillations or absorbtion of rebound due to the 
friction between the spring leaves. The spring fork of the Indian 
motorcycle is of the trailing type, which means that the hub axle 
follows the forks instead of having the hub mounted ahead of the 
fork as is also common practice. The advantage of the trailing hub 
is not as clearly realized as it should be. With the forms in which 
the hub is carried ahead of the fork, when the wheel is raised, it is 
apt to produce an upward movement of the entire front end of the 


Design and Construction of Frame Parts 389 



Movable ™ 
sForb, Member 


litliSi 


Fig. 229.—Leaf Spring Used on the Eagle Motorcycle to Control 

Movable Fork Member. 









390 


Motorcycles , Side Cars and Cyclecars 



Fig. 230.—The Indian Cradle Spring Fork. 


machine because a certain portion of the shock is transmitted by the 
hub carrier link directly to the fixed fork members as the wheel sur¬ 
mounts the obstacle. With the trailing hub construction, which is 
clearly outlined at Fig. 230, any movement of the wheel will affect 
only the shock absorbing spring. 

The advantage of the trailing hub construction may be readily 













Design and Construction of Frame Parts 391 

< 

grasped by comparing its action to that of a wheelbarrow when it 
passes over a raised object. If a wheelbarrow is pushed against a 
curb, for instance, it will be found difficult to force it over the ob¬ 
struction, whereas if it is pulled over it will surmount a high curb 
with comparatively little effort on the part of the person wheeling it. 
The usual method of supporting the front wheel ahead of the fork 
may be likened to pushing a wheelbarrow over; the trailing hub 
action is the same as when it is pulled over the obstruction. 

The fixed fork member of the Indian machine is well braced by a 
tubular arch member extending from the top of the steering column 
to the lower portion of the fixed fork. The hub carrier links are at¬ 
tached at their front end to the fixed forks, carry the wheel hub at 
their center, and the movable forks at the back end. The curved 
lower leaf of the shock absorbing spring provides a certain degree of 
flexibility which makes the wheel respond to slight irregularities of 
the road surface, and when greater resistance is encountered the 
entire spring is brought in action because the movable fork member 
exerts its pressure against the lower leaf at a point calculated to 
bring the remainder of the spring leaves in action. 

The foreign spring forks vary from the American designs, and the 
preference seems to be for coil springs as shock absorbing members, 
which are invariably exposed. A number of typical English spring 
forks are shown at Fig. 231. In the member outlined at A, the wheel 
is carried in a substantial movable fork member, that is secured to 
the member passing through the steering head by means of distance 
links which permit a certain amount of up and down motion, but 
which do not allow the wheel to move backward appreciably. In 
most American designs, the wheel may move backward as well as up 
and down. At the lower portion of the piece passing through the 
steering head a pair of spiral springs are mounted which are attached 
at their lower ends to extensions brazed to the fork tube. When the 
wheel meets an obstruction, its upward motion is resisted by the 
springs which are under compression while the violent rebound is 
checked by the tension resistance of the spring. In the form shown 
at B, the fixed fork member is fulcrumed on a pair of links which are 
attached to the piece passing through the steering head. The shock 
absorbing spring is also secured to the steering head member and 


392 


Motorcycles , Side Cars and Cycle cars 



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Design and Construction of Frame Parts 


393 



Movable Link 


Friction Stock 

Absorbing 

VUnOe 


Recoil Check 
Spring 


resists upward motion or vertical travel of the fork member, which 
can move in that plane as the distance links oscillate on their bear¬ 
ings. The upward motion is resisted by the upper coil spring while 
the recoil is checked by a suitable member at the lower part of the 
steering head. Both springs are under compression. 

Another form which is 
very similar to the 
American design de¬ 
picted at Fig. 228, with¬ 
out enclosed springs, is 
shown atC. In this, the 
lower of the two springs 
is a compression member 
that is provided to absorb 
the shock, while the 
shorter of the two or up¬ 
per spring is used to 
check ' the recoil. The 
hub in this construction 
is carried in a movable 
fork member which is 
kept in proper relation 
with the fixed fork by 
suitable distance links. 
A point that should be 
noted by the reader is 
the system of applying a 
pair of brakes that act 
against the front wheel 
rim on all three of the 
forks shown at Fig. 231. This brake is actuated through the medium 
of Bowden wire control running to a suitable handle on the steering 
bar. The U-shape member carrying the brake blocks or contact 
shoes is guided at its lower ends by clips secured to the fork side, 
while it is steadied at the upper end by a bearing through which the 
wire or a lifting rod passes 

Spring Supported Seat Post. —After the springing of the front 




Load 

Spring 


Fig. 232.—Spring Supported Seat Post of 
Reading-Standard Motorcycle. 






Motorcycles, Side Cars and Cyclecars 


394 



Fig. 233,—Spring Seat Post Used on Eagle Motorcycle. 










Design and Construction of Frame Parts 395 

end has been satisfactorily accomplished by the use of spring forks 
some of the designers began to consider the best method of eliminating 
the jar at the rear end of the machine. Some of the manufacturers 
have adopted a resilient frame construction with the idea that this 
would suspend the power plant on springs, as well as the rider. Other 
makers contend that the spring supported saddle coupled with a 
resilient spring fork is all that is needed to insure comfort of the rider, 
and reduction of shock on the machine. 

The spring seat post attachment employed on the Reading-Stand¬ 
ard motorcycle has demonstrated its efficiency and is very simple. 
As is true of the spring fork previously described, the resilient support 
of the saddle is attained by the use of coil springs protected by and 
housed in a tubular housing hinged at its lower portion just forward 
of the pedal crank hanger, and maintained in proper position at the 
upper end with a movable distance member or link. The seat post 
is extended to form a plunger that is guided by a suitable bearing at 
the upper end of the spring housing. The long coil spring is the load 
carrying member, while the shorter spring at the upper end is a recoil 
check. Another feature that tends to prevent too rapid movement 
of the seat post is the friction shock-absorbing hinge by which the 
movable link is held to the seat post tube. 

The spring seat post used on the Eagle motorcycle, and illustrated 
at Fig. 233, is similar in construction to that just described, though it 
is different in detail and application. The seat post is hinged at its 
upper end to a clip attached to the upper frame tube. It is adapted 
to bear on a plunger member that projects through the seat post tube, 
which also serves to house the load-carrying and recoil spring. A 
simple application of a spring-supported seat post is shown at Fig. 
234. The forward end of the seat post is hinged to the frame, while 
the rear end is secured to a conical spring that bears on a supporting 
member attached to the rear fork. 

The method of mounting the saddle on the Yale motorcycle, 
shown at Fig. 235, is similar except that two springs are used, one at 
either side of the seat post tube in supporting the saddle. These are 
coil springs and are intended to supplement the action of the members 
with which the saddle itself is provided. Another application of a 
spring seat post is shown at Fig. 236, as applied to the Fielbach 


396 


Motorcycles , Side Cars and Cyclecars 


motorcycle. The saddle supporting member is in the form of a bell 
crank, the long arm of which carries the saddle, while the short arm 
is attached to a plunger that works through the lower of the two 
upper frame tubes which serves as a housing to retain the load¬ 
carrying and recoil-absorbing members. 

Spring Frames. —There is a marked distinction between spring 
seat posts and spring frames, and this is well shown by comparing 



Fig. 234.—Application of Single Coil Spring to Support Seat Post of 

Thiem Motorcycle. 

the two different methods shown at Fig. 237. That at A is a simple 
spring frame, which means that the weight of the rider is carried by 
a frame which in itself is capable of movement, and that the same 
frame to which the power plant is secured also directly supports the 
weight of the rider. The rear hub of the Pope motorcycle is mounted 
in simple forged yokes that are guided by plungers extending through 
bosses at the end of the U-shape brackets attached at the rear of the 
frame. The heavy coil springs are under tension and the tendency of 




Design and Construction of Frame Parts 


397 



Fig. 235.—Double Coil Spring Supported Saddle Carrier of Yale 

Motorcycle. 

the upward movement of the rear wheel when it strikes an obstruction 
is to extend rather than compress them. The spring-supported seat- 
post representative of the other construction, shown at Fig. 237, B, 
also includes a coil spring under tension. The seat post is guided by 
distance links, one end of the spring being attached to the frame, 
while the lower end is secured to the movable seat-post member. 

The cradle spring frame utilized on the Indian motorcycle is con¬ 
ceded to be one of the biggest steps forward ever made in the develop¬ 
ment of the motorcycle frame. The construction is not unlike that 
of the spring fork except that two load-carrying springs are used, one 
at each side of the wheel. The wheel hub is carried in a movable rear 
fork stay hinged at its forward end to the lower portion of the tube 









398 


Motorcycles , Side Cars and Cyclecars 



Fig. 236.—Method of Housing Spring Controlling Action of Fielbach 

Seat Post in Frame Tube. 


that takes the place of the seat-post mast of conventional design 
frames. The load-carrying springs are attached to a semi-steel cast¬ 
ing member in the form of a horseshoe that takes the place of the 
usual seat-post cluster. A movable rear fork member is attached to 
the springs in the same manner as the movable fork member of the 
spring fork assembly is, and is hinged at its lower portion to the hub¬ 
carrying plates. It will be evident that with this construction the 
rear wheel may move independently of the main portion of the frame 
that carries the weight of the rider and the power plant, and that the 
combination of this member with the effective spring fork should not 



Fig. 237.—Examples of the Two Differing Methods of Providing 
Resilient Support for the Rider. A—The Pope Helical Tension 
Spring Frame. B—Tension Spring Supporting Movable Seat Post. 













399 


Design and Con sir net ion of Frame Parts 



Fig. 238.—The Indian Cradle Spring Frame. 


only provide for maximum comfort of the rider but contribute 
materially to the long life and endurance of the mechanism by in¬ 
sulating it from the destructive road shocks in a much superior 
manner to that which obtains in the conventional construction where 
the air-filled tire is the only resilient support. 

Two spring frame constructions in which coil springs are used are 
shown at Fig. 239. That at A is the form used on the Merkel, and 
has been a feature of this machine for several years. The rear por¬ 
tion of the frame, which is comprised of the forks and rear-fork stays, 













400 Motorcycles, Side Cars and Cyclecars 

operates in the same manner as the spring forks in which the enclosed 
coil springs are used. The rear-fork stay members are employed to 
house the coil springs, while the front end of the fork assembly is 
hinged to the crank hanger in order to permit free movement of the 
rear portion of the frame. The method of incorporating a heavy 
compression spring in the frame of the N. S. U. motorcycle, a foreign 
design, is shown at Fig. 239, B. The application of four laminated 
leaf springs to support the rear wheel of an English four-cylinder 



Fig. 239.—Two Methods of Incorporating Coil Springs in Spring 
Frames. A—Application in Merkel Rear Fork Stays. B—Com¬ 
pression Springs Used on N. S. U. Model. 


motorcycle employing worm drive is shown at Fig. 240. In view of 
what has been presented before, and the complete explanations that 
have been given of spring fork and spring frame action, the method 
of operation of these various forms should be clearly grasped. 

Saddles and Tandem Attachments. —The first motorcycle in¬ 
cluded practically all the parts of the bicycle without much change, 
and it was some time before some of the parts were altered or en¬ 
larged, even after considerable improvement had been made in motor 














Design and Construction of Frame Parts 401 

design and in the construction of the mechanism. One of the fittings 
that was not changed for several years because the designers had all 
they could do to make the mechanism reliable was the support or 
saddle for the rider. The saddles that had been used in bicycles were 
of simple form, usually consisting of a light wooden or steel frame 
covered with leather; in some cases a padding would be interposed 



Fig. 240.—Method of Carrying Rear Wheel by Four Leaf Springs on 

T. A. C. Motorcycle. 

between the leather covering and the base. Bicycle saddles were 
narrow, and they were very satisfactory on those machines where 
the riders weight was distributed to some extent on the crank 
hanger through the efforts made and pressure applied to the pedals 
to propel the vehicle. With the motorcycle, the rider did not have to 
pedal any more than was necessary to start the machine, which meant 
that practically all of his weight would rest on the saddle. Several 







402 


Motorcycles , Side Cars and Cyclecars 


forms of bicycle saddles were made that provided a wide support, but 
it was found that these materially interfered with the effective action 
of the rider’s limbs when pedaling. This objection did not obtain in 
the motorcycle and the saddles were gradually increased in size, both 
in length and in width, until the forms used to-day provide a secure 
and comfortable seat. It was not desirable to have a very resilient 
saddle on a bicycle because the spring detracted somewhat from the 
effectiveness of the pedaling. On a motorcycle, however, it was soon 
learned that it was much more uncomfortable to sit on an inflexible 
non-yielding seat on a machine going 35 or 40 miles an hour than was the 



Fig. 241.—Typical Motorcycle Saddles. 


case when traveling but one-third that speed on a bicycle. The saddle 
manufacturer was not slow in devising wide seats that were provided 
with substantial spring members in order to make them easy riding. 

Two modern saddles are shown at Fig. 241. That at A consists 
essentially of a metal frame over which a leather seat is placed, the 
leather being kept under tension by the coil spring at the front end. 
This spring gives somewhat under the rider’s weight, though the main 
reliance for easy riding is upon the coii springs at the rear of the 
saddle. The form shown at B is similar in construction as far as the 
frame work is concerned, except that the seat is formed to conform 
to the anatomy of the average rider and has a padded cushion inter¬ 
posed between the leather covering and the metal frame. 

The arrangement of the springs used to support the rider in the 






Design and Construction of Frame Parts 403 



Fig. 242.—Showing the Two Forms of 
Springs Used in Supporting Motorcycle 
Saddles. 


usual motorcycle saddle 
as well as the general 
construction of the form 
in which coil springs are 
used is clearly outlined 
at Fig. 242, A. The 
metal frame work with 
the leather coverings 
removed to show the 
arrangement of the 
parts of the Persons 
Champion Saddle is 
shown at Fig. 2*43. Coil 
springs are not the only 
type that have been 
adopted in saddle con¬ 
struction. A form in 
which leaf springs are 
used to support the 
rider’s weight is shown 
at Fig. 242, B. Practic¬ 
ally all saddles are pro¬ 
vided with an adjust¬ 
able clamp that permits 
of tilting the saddle to 
some extent and moving 
it back and forth on the 
seat post tube to adjust 
the seat member for 
different builds of riders. 


While some of the early motorcycles were made in a tandem form, 
i, e., just the same as the two-passenger bicycles except for the addi¬ 
tion of the power plant, this form of construction is now abandoned. 
The reason for discarding the tandem was that the machine was un¬ 
wieldy and hard to handle if but one person was riding. For this 
reason, tandem attachments that would convert the ordinary form of 
one-passenger motorcycle so that two people can be carried effectively 








































































404 Motorcycles , Side Cars and Cyclecars 

have been evolved. A typical tandem attachment removed from the 
machine is shown at Fig. 244, while a similar device attached is de¬ 
picted at Fig. 245. The tandem attachment in its simplest form con¬ 
sists merely of a supplementary rear fork member carrying a pair of 
foot rests or pedals at its lower end, and a saddle at the upper part. 
A brace extends from the top of the fork to the seat post cluster of the 
machine, and in most cases this brace carries a pair of non-movable 
handle bars by which the passenger may steady himself. 



Why Powerful Brakes are Necessary. —It is now generally con¬ 
ceded by manufacturer and rider alike that the motorcycle of to-day 
is practically a two-wheeled automobile capable of speeds rarely at¬ 
tained by the larger conveyance. Engines used are rated at from 
7 to 9 horse-power, and these will usually develop twice their nominal 
rating. Larger motors call for heavier frames to carry them and the 
rider safely, more powerful transmission systems are fitted and spring 
frame and forks are also required to insure comfortable riding at high 
speeds over ordinary roads. All control elements must also be de- 














Design and Construction of Frame Parts 


405 


* < 


signed with a view of giving the rider positive mastery of the machine. 
When one considers the momentum it is possible to attain with a 
vehicle weighing, with average rider, nearly 400 pounds, and capable 
of a speed of 75 miles per hour in many cases, the need of a positive 
retarding member or brake can be properly realized. Brakes designed 
primarily for bicycle service and increased in size without due regard 
to the stresses obtaining in motorcycles, cannot work adequately or 

prove enduring. The 
brake as well as the 
other parts of the ma¬ 
chine must be increased 
in size and capacity to 
correspond in efficiency 
to the larger power 
plants now fitted. The 
problem is therefore es¬ 
sentially one of automo¬ 
bile design, and can 
only b e solved by a 
correct application of 
motor car engineering 
principles. 

Why Coasting, 
Driving and Braking 
Hub is Used. —One of 
the most important ac¬ 
cessories developed for 
the bicycle trade, and one which has contributed materially to the 
expansion of that business by promoting the comfort and safety of the 
rider was the coasting and braking hub. In this device, the motor¬ 
cycle manufacturer obtained a rear hub construction, already highly 
developed, that was just as well suited in principle to motorcycle 
use as it was to the bicycle, though applied in a slightly different 
manner. In bicycle service, it is provided to give the rider an oppor¬ 
tunity to stop pedaling on down grades or smooth roads with favoring 
winds, and yet permits him to keep control of the bicycle, because a 
slight back pedal action applied a brake to the wheel. 










406 


Motorcycles , Side Cars and Cyclecars 


On a motor-propelled cycle the motor does the driving normally, 
and the pedals are only brought in action when it is desired to propel 
the machine by foot power to start the motor. As soon as .the engine 
starts, the coasting feature comes into play, and the action is just the 
same as though the rider of a foot-propelled cycle was taking ad¬ 
vantage of down grade. The pedals provide a rest for the feet, and 
the back pedaling or reverse pressure begins to bring the brake in 
action any time it is necessary to retard the speed of the machine. 


Fig. 245.—Application of Tandem Attachment on Henderson Motor¬ 
cycles. 

The rear sprocket of a chain-drive machine is attached directly to the 
hub shell; the belt pulley, if that system of transmission is used, can 
be secured to wheel rim or to hub shell, as desired. The only difference 
in principle between a coaster hub intended for motorcycle work and 
the similar device made for bicycles is that two methods of driving 
the rear wheel are provided, one by mechanical power to a member 
rigidly secured to the hub shell, the other by foot power through the 
medium of a friction clutch that automatically engages the hub shell 
interior as soon as the pedals are pushed forward. 











Design and Construction of Frame Parts 407 

Requirements of Pedal Drive Mechanism. —The requirements 
of the pedal drive mechanism are well known at the present time, and 
that employed has demonstrated its correctness in theory and prac¬ 
tical application by years of actual use in millions of bicycles. The 
basic principle of the spirally threaded member and laterally shiftable 
connector to drive the hub, declutch to provide a free wheel and to 
apply the brake by further movement has been developed in this 
country to a state of practical perfection. The best argument in favor 
of this pedal drive mechanism is that a simple and successful coaster 
brake cannot be built without incorporating this system, and that all 
devices on the market embody this principle. The construction is 
such that the hub is driven smoothly and positively whenever the 
pedals are rotated forward, the hub is free to rotate independently 
of the pedal drive sprocket as soon as the feet cease rotating and a 
reverse motion of the pedals or back pedaling action will apply the 
brake without slipping. Coaster brakes have been made with 
ratchets, ball or roll clutches, etc., but these have not been as success¬ 
ful, reliable or enduring as the double taper cone principle of driving 
and brake actuation universally applied. 

What Brake End Should Do. —While the requirements of the 
pedal drive mechanism were well understood, the principles making 
for efficient brake action of motorcycle hubs were not realized so com¬ 
pletely, and it is on this portion of the mechanism that most manu¬ 
facturers disagree. To begin with, the essential requirement is that 
the brake member be capable of retarding the cycle velocity to any 
degree from a simple and momentary slowing down to a quick, 
emergency stop. This condition is not hard to meet, almost any form 
of brake will do it, when new, clean and in proper adjustment. The 
successful and really practical brake must be one that will provide 
this essential prompt braking action but it must do it in a gradual 
manner, because a harsh acting brake will impose injurious stresses 
in the entire mechanism of brake and related wheel and frame parts. 
The practical brake should be a form that will not need constant 
adjustment, the essential mechanism should be thoroughly protected 
from the abrading influence of road dirt, the brake member should 
be housed in and supported in a manner that will preclude liability 
of rattling. The brake parts should be of material that will not only 


408 


Motorcycles , Side Cars and Cyclecars 



mgggm 


1 


t_ever 


Fig. 246.—External Constricting Band Brake Used on Harley- 

Davidson Belt Drive Model. 

have a high degree of resistance to wear in service, but the members 
that come in contact to provide the braking action should also have 
a high degree of frictional adhesion because it is the absorption of 
power by the frictional contact that retards the momentum of the 
machine. The design of the brake end should be such that the parts 
will not drag or tend to engage each other when the brake is released, 
and the arrangement of braking members should be such as to provide 








Design and Construction of Frame Farts 


409 


immediate cessation of braking effort as soon as the pressure exerted 
by the rider on the actuating members ceases. 

W hile the brake should be easy to apply so the maximum braking 
effect will be obtained without too much effort on the part of the 
rider, at the same time, the brake should not be so sensitive that it 
can be applied inadvertently through unconscious back pedaling. 
The ability of the brake end to function properly even though flooded 
with the oil or grease used in lubricating the hub bearings and interior 
mechanism is also essential. 

Let us carefully consider the force needed to afford positive control 
of the modern motorcycle, then become familiar with the principle of 
braking action, and a careful analysis of the construction of various 
types of brakes will permit the rider to form his own conclusions re¬ 
garding the type that best meets all of the requirements previously 
enumerated. 

Force Required at Brake. —The most any brake can do is to skid 
the wheel to which it is applied. If it can accomplish this, it is ade¬ 
quate to cope with any of the normal operating conditions. The 
amount of force needed to lock the wheel depends upon the amount 
of the total weight of the machine supported by the wheel to which 
the braking effort is applied, and the relative diameters of wheel and 
brake member. Much less force will be needed to stop a wheel if the 
brake is applied near the tire than if it acts near the axle. Structural 
limitations make it necessary to locate the brake in the hub so it can 
be actuated positively by back pedaling mechanism that will be en¬ 
tirely protected and properly lubricated but at the same time it is 
possible to follow automobile practice and provide a drum for the 
brake to act against that will be of such diameter that the wheel may 
be controlled without too much exertion on the part of the rider, or 
producing undue stress on the brake members. 

Assume that the machine we are to stop is a powerful twin weighing 
250 pounds with tandem attachment and carrying a passenger load 
of 300 pounds, that being the weight of two average riders. This 
makes a total of 550 pounds, and we can justly assume that 450 
pounds will be supported by the rear wheel. The amount of adhesion 
between the tire and the ground is generally taken as 60 per cent of 
the weight on the wheel, so we will have traction enough so a retarding 


410 


Motorcycles , Side Cars and Cyclecars 


force must be applied at the brake drum equivalent to the adhesive 
force of 270 pounds at point of contact between wheel tire and the 
ground. If the wheel is 28 inches in diameter, it will have a radius 
of 14 inches. The moment at the axle center due to the leverage 
factorwould be the adhesive pressure times wheel radius which would 
give a value of 3,780 inch pounds at 1 inch from wheel center. If 
the brake; had an effective diameter of but 3 inches, as would be the 
case if it-was carried in the hub shell, we would be forced to apply 
a retarding effect of 2,520 pounds to lock the wheel. With a brake 
drum 6 inches in diameter, it would take only 1,260 pounds retarding 



Fig. 247.—Application of Band Brake Actuated by Back Pedaling 

Ratchet Mechanism. 

t 


force to skid the wheel. If a brake block was applied directly to the 
tire, it would take but 270 pounds adhesive force, or the same amount 
as maintains traction, to stop the driving member. 

It will be apparent that the larger diameter brake members require 
less effort to stop the wheel than those forms in which the braking 
effect is exerted near the axle. This use of a large brake drum not 
only makes for easier brake operation on the part of the rider but 
conduces to longer life of the parts because of the lessened stresses on 
the brake anchorage members and also lower unit stress on the 
materials in contact. While it is very desirable to have a compact 











Design and Construction of Frame Parts 


411 


brake assembly, still it is more important to use the requisite pro¬ 
portions that will insure positive braking under all conditions even 
if compactness and lightness are sacrificed by making the brake drum 
and brake shoes of adequate diameter, and all parts heavy enough 
so they will have an ample margin of safety over the actual require¬ 
ments. Where human life and safety are concerned, it is best to err 
on the safe side, and the addition of a few ounces of metal is some¬ 
times all that is needed to make a part of doubtful strength one with 
a large enough margin to guard against the weakening influence of 
hidden flaws or insure against breakage when subjected to abnormal 
stress. At the other hand, the brake parts require careful designing 
to keep the weight down and retain strength, and materials of con¬ 
struction must be selected intelligently to insure absolute reliability 
and endurance. 

Principle of Brake Action. —The friction form of brake is that 
generally applied to all forms of vehicles. The principle of action 
may be concisely expressed by saying that if a fixed member is brought 
to bear against a rotating one, the friction between them will bring 
the one in motion to a stop. The time needed to stop a rotating 
body depends entirely upon the amount of friction present between 
the braking members. This in turn depends upon the co-efficient of 
friction existing, which varies with the nature of the materials in con¬ 
tact, the effective diameter of the brake members and the pressure 
holding the parts together. We have seen why large diameters are 
more desirable than small ones. 

The amount of surface in the brake is not as important as effective 
diameter, because the braking effort depends primarily upon the 
diameter of the surfaces rather than their width. For example, there 
would be no difference in braking efficiency as relates to retarding 
power between a brake band J4 inch wide or 2 inches wide if the 
diameter was the same. The wider brake band would provide an 
important advantage of having greater life because the braking 
pressure would be distributed over a larger area. It would not be 
any more effective as a brake, however, than the narrower member. 
It is generally believed that braking power depends upon the surface 
in contact, but this is not true. A brake of small diameter might have 
three times the surface of one of twice the diameter, yet the one with 


412 


Motorcycles , Side Cars and Cyclecars 


lesser surface would be twice as effective as a brake. The capable 
designer will always endeavor to provide surface enough to prevent 
undue depreciation, and will employ materials in contact that will 
have a high degree of resistance to deformation. In some forms of 
brakes, however, the large amount of surface provided is an actual 
detriment to efficient brake action and serves no useful purpose. 

The materials employed for brakes depend largely upon the design, 
and in every case these should be chosen with two considerations in 
mind, the most important being the endurance of the material and 
ability to keep its shape under pressure as well as high degree of 
resistance to abrasion. The material should not be affected by the 
heat generated when the brake is used, nor should it become decom¬ 
posed or its efficiency reduced materially by oil deposits. Another 
consideration, but one of secondary importance, if it calls for the 
sacrifice of the qualities previously enumerated, is to employ sub¬ 
stances having a high degree of frictional adhesion. 

Friction Co=efficient of Various Materials.—In brake design, 
engineers must seek to increase friction, whereas in bearing con¬ 
struction every effort is made to reduce it. The following brief notes 
on the characteristics of friction and a definition of the meaning of 
friction co-efficient will permit even the reader not thoroughly posted 
on mechanical subjects to understand clearly what is meant when 
the terms are used. 

Friction acts on all matter in motion, and is present as a retarding 
influence that requires expenditure of power to overcome. As a rule, 
augmenting the pressure will increase the friction, while lessening the 
load will reduce it. Friction increases with the roughness of surfaces 
in contact and decreases as they become smoother. Friction tends to 
bring everything in motion to a state of rest, and, in so doing, 
mechanical energy is converted into heat which is dissipated and lost. 

A simple experiment to show what coefficient of friction means can 
be made by anyone. This consists of drawing a block of iron or other 
metal across a wood table top by means of weights suspended by a 
cord passing over a pulley at the edge of the table, and then attached 
to the block, in order to avoid a sharp bend and eliminate lost energy 
as much as possible. Assuming the block is smooth, also the surface 
of the table, the first trial can be made with the surfaces absolutely 


Design and Construction of Frame Parts 413 


dry. Weights are added to the cord until enough have been placed 
thereon to move the block on the table. The weight required to move 
the block divided by the weight of the block will equal the coefficient 
of friction for these surfaces. If the block of metal weighs 50 pounds, 
and the amount of weight necessary to move it is 25 pounds, the 
coefficient of friction is 25 divided by 50, or 0.50. If the surface of the 
table is greased with tallow, and the under surface of the block 
covered with oil, it will be found that considerably less weight will be 
needed to move the block, proving that the friction has been reduced 
by lubrication. 



Fig. 248.—External Constricting Band Brake Used on Henderson 

Motorcycles. 


This explains why it is desirable to lubricate bearings, whereas 
on first thought it would seem that the best braking effort would 
occur between perfectly dry materials. It would also appear that the 
softer and rougher materials which have greater friction would be 
better for brake construction than hard and smooth ones. This 
would be true if braking effect was all that was to be looked for, and 
if the factors of gradual application of retarding force and endurance 
of brake members could be disregarded. As it is important that 
depreciation be reduced to a minimum, and that all shock should be 
avoided when braking, one can see a logical reason for the use of 










































414 


Motorcycles , Side Cars and Cyclecars 


materials that would have less friction adhesion though greater resist¬ 
ance to wear, and which provide smoother brake action. 

The materials ordinarily used for brakes and their friction coeffi¬ 
cients follow: 


Asbestos Fabric on Dry Metal. 0.30 

Asbestos Fabric on Oily Metal. 0.12 

Metal to Dry Metal. 0.15 

Metal to Oily Metal. 0.07 


These values mean that if an asbestos fabric block or band bears 
against a dry metal drum, less than one-third or 30 per cent of 
the pressure maintaining the parts in engagement will be available 
for stopping brake drum rotation. If the asbestos fabric works 
against an oily surface, the frictional adhesion or braking force is re¬ 
duced to but one-eighth of the pressure keeping the parts together. 

Asbestos fabric is a soft, yielding material that is very effective if 
used as an external brake, but it is entirely unsuited for use where 
much oil is present. While it provides a gradual braking action, it is 
not capable of withstanding as high unit pressures as metal, so a larger 
surface must be provided to insure against untimely depreciation. As 
it is a rough-surfaced material that depreciates as used, constant ad¬ 
justment and renewal will be necessary to keep the brake in a satis¬ 
factory condition. For this reason, this material is better adapted 
to external constricting band brakes than to other forms, because it 
can be easily reached for adjustment, and it will be free from oil 
deposits. 

A metal is always used as one brake member, usually the rotating 
one, and sometimes it is used for both members, fixed as well as 
movable. While metal does not possess as much friction as the as¬ 
bestos fabrics, it does not depreciate through action of oil, and it can 
be used with higher unit pressures than the softer fabric. The surface 
need not be so great if the metals are properly selected. When used 
in motorcycle brakes, the revolving metal drum is usually harder than 
the fixed shoes or retarding members, and in all cases efforts are made 
to use different metals in combination such as bronze against steel. 
The metals are much more enduring if lubricated, and the oil film 
serves to cushion the shock of braking by providing gradual applica- 







Design and Construction of Frame Parts 415 

tion, as well as reducing the liability of dragging or heating, when 
brake members are released, should there be slight frictional contact 
between them. Metal brake shoes or discs are therefore better suited 
for internal brakes than asbestos fabric faced bands, if there is as 
much oil present as exists in motorcycle hubs. 

Leading Types of Brakes. —The most common forms of brake 
are the various band or shoe types, and the braking members may 
act against either the inner or outer drum peripheries. The external 


Fig. 249.—Internal Expanding Brake Used on Chain Driven Harley- 

Davidson Models. 

band forms, shown at Figs. 246 to 248 inclusive, tighten around the 
drum, the internal form as Fig. 249 expands inside the drum or hub 
shell. There is still another form of external brake in which a friction 
block bears against the wheel rim or the belt pulley when that method 
of driving is employed. The external band is usually a flat steel strip 
faced with asbestos fabric which is sometimes made wedge shaped 
(Fig. 250) where it fits into the brake drum to provide greater fric¬ 
tional adhesion. The wedge-shape band offers an important ad¬ 
vantage, in that it provides a positive grip, but it has an equally great 












416 


Motorcycles , Side Cars and Cyclecars 


disadvantage in that it is apt to engage too suddenly, and then again 
it may wedge in place so tightly that the spring provided to release 
it will not be effective, and it must be pried out of the V-groove in 
brake drum. The flat band provides more gradual braking, and if 
made of proper diameter is amply effective. 

The brake block form shown at Fig. 252 has the fault that it cannot 
be easily operated through the pedals, or incorporated as a part of 
the hub. It is a separate attachment that is used in this country only 
for emergency brake service, being controlled by a separate pedal 
distinct from those utilized in driving the hub. The external brakes 


have a great disadvant¬ 
age, inasmuch as they 
are exposed to dirt, and 
collect this matter which 
acts as an abrasive that 
promotes wear of friction 
material and drum. 
They are also liable to 
become loose and rattle, 
and they all have more 
small parts than the 
simple internal shoe 
forms. While these 
external brakes are good, 
they are not ideal by 



Fig. 250.—The Corbin V Band External 
Contracting Brake. 


any means, and if only one brake member is fitted this should be 
preferably of the internal form. A combination of two brakes, one 
internal and one external, is provided on some machines, as shown 
at Fig. 251. 

The internal brakes are offered in three classifications. The form 
using a pair of shoes expanded in a drum by a cam is the most popular. 
The internal ring form, in which the fixed member acts against the 
inside of the hub shell, is at a disadvantage on account of its small 
diameter and the great wear due to the excessive pressure necessary 
to have it grip the hub shell interior with sufficient force to stop the 
wheel positively. These also are a form that will not release promptly 
at all times, and are likely to stick if applied too suddenly. 












Design and Construction of Frame Parts 


417 



Fig. 251.—Double Brake Combination Used on Indian Two Speed 

Motorcycles. 

The multiple disc brake (Fig. 255) is a form in which a large number 
of braking members are used, one-half being rotatable with the hub 
shell, the others being fixed to the axle. Suitable mechanism is inter¬ 
posed between the pedals and discs so the brake elements are brought 
together with considerable degree of pressure. This form of brake, if 
copiously lubricated, will provide smooth brake application, and also 
offers a large amount of frictional surface. It has the disadvantage of 
not always releasing promptly, because as the oil is squeezed from 
between the discs by the braking pressure, the plates tend to adhere 
together when pressure is released because of the partial vacuum 



























418 


Motorcycles , Side Cars and Cydecors 



Fig. 252.—Application of Foot Actuated Brake Block to Belt 

Pulley Rim. 


existing between them. If lubrication is neglected, or if the brake 
is used for long periods, as in mountainous sections, there will be 
sufficient heat generated by the braking friction to cut or roughen 
the discs, and even to actually deform them. Under such conditions, 
the brake becomes harsh in action, no matter how much oil is used, 
and will also drag even when released because the rough surfaces have 



Fig. 253.—Block Brake Fitted for Dual Actuation as Either Pedal at 
Foot Rest or Back Pedalling Will Apply Brake. 































Design and Construction of Frame Parts 419 

myriads of microscopic projections that tend to interlock as the 
movable discs revolve by the fixed members. 

The internal brake in which bronze shoes of ample size are brought 
into engagement with a hardened steel drum interior offers a large 
number of advantages. To enumerate these briefly, we have: First, 
utmost simplicity; second, strong parts; third, high retarding power; 
fourth, freedom from dragging; fifth, efficient braking with oil between 
the surfaces; sixth, gradual or immediate brake application as desired; 
seventh, all brake parts lubricated and kept clean; eighth, complete 



Fig. 254.—Showing the Application of Dual Brake Control on the 

Flying Merkel Motorcycle. 


enclosure of brake members; ninth, absolutely prompt release of brake 
shoes; tenth, braking-force obtained by minimum effort; eleventh, 
brake actuated directly from pedals by strong, simple mechanism; and 
twelfth, maximum endurance because of the ability of the bronze 
shoes to resist wear due to abrasion better than any other material 
and practical indestructibility of the hardened steel brake drum. 
This endurance is augmented by the oil always present between brake 























420 Motorcycles , Side Cars and Cyclecars 

surfaces and the lessened strain on the parts, because the oil film 
absorbs the first shock due to brake application. 

Operation of Typical Braking and Coasting Hub. —The New 
Departure, Model L, has been devised with special reference to the 
requirements of motorcycle service. As will be evident from in¬ 
spection of illustration, Fig. 256, the general construction of the pedal 
drive mechanism follows the well-established practice except that all 
parts are heavier and stronger than anything devised to date. Begin¬ 
ning with a inch diameter axle, the entire mechanism has been 



augmented in size to conform to automobile rules of practice rather 
than adhering to bicycle construction. The ball bearings are large 
enough for the wheel of an automobile, and, in addition to the use 
of large balls, an automobile type or heavy separator is utilized. 

Referring to the illustration, we see that the main portion of the 
device is a hub shell carrying a brake drum and flanges to which the 
spokes are secured. The outer ball races are formed in the hub shell, 
which is glass hard at the point where the balls run. The brake drum 
is a steel stamping 6 inches in diameter, and securely attached to the 
hub shell flange by a process of electric spot welding, which fuses the 
members at a number of points to form an intimate bond between 









































































































Design and Construction of Frame Parts 421 

















































































































422 


Motorcycles , Side Cars and Cyclecars 


them. Contrast this to the usual method of riveting or keying such 
a member in place and it will be apparent that every precaution has 
been taken to avoid any trouble from loose fastenings. In the chain 
drive type the sprocket-retaining flange is secured to the brake drum 
by the same process. 

The pedal-chain sprocket is attached to a rotatable member sup¬ 
ported on an adjustable ball bearing, and at the inner end the member 
is provided with a spiral thread. This male thread fits into a corres¬ 
ponding female portion in the laterally shiftable member, and the 
angle of the thread is such that when the pedal sprocket is rotated 
forward, the spiral draws the shiftable member against the tapering 
female clutch member forming part of the hub shell. The clutching 
action connects the sprocket to the hub and rotates it. If the pedals 
are held from moving, the clutch releases automatically, and the hub 
shell can run independently of the foot pedal mechanism. If the foot 
action is reversed, or the pedal sprocket rotated backward, the female 
clutch member in the inner portion of the laterally shiftable connector 
will be forced tightly against the male taper of the brake cam-lever 
actuator, which can oscillate on the axle only in the direction necessary 
to apply the brake. 

If one refers to sketch of brake end at Fig. 257, it will be seen that 
the oscillating motion of the actuator transmits a similar motion to 
the end of the lever of which the brake-shoe spreader cam forms a 
part. Any displacement of the cam will spread the brake shoes apart, 
and they will fulcrum on the supporting pin secured to the brake end 
plate. The brake shoes then take up the clearance existing between 
their outer surface and the inner surface of the drum, and exert a 
retarding effect in proportion to the amount of pressure applied by 
back pedaling. 

As soon as the back pedaling pressure is released, the springs serve 
to bring the brake shoes out of engagement immediately. The upper 
one holds the brake shoes firmly against the cam, the lower one returns 
the cam lever back against its stop and also brings the oscillating 
actuator back in position ready for further brake application when 
the laterally shiftable member clutches it. 

The brake shoes and spreader cam are carried by a drop forged 
steel plate which has an arm formed integrally that is intended to be 


Design and C onstruction of Frame Parts 


423 



Fig. 257.—Showing Method of Brake Shoe Actuation by Cam Action 

in Internal Expanding Brake. 


attached to the frame members and serve as an anchorage to prevent 
brake shoe rotation. 

How Rider’s Effort is Multiplied .—A diagram is presented at 
Fig. 258 for the benefit of those mechanically disposed, which demon¬ 
strates clearly how the pressure of the rider’s foot on the pedal is 
multiplied, and how much pressure is available between brake shoes 
and drum to stop the wheel. This shows the effectiveness and correct 
design of the internal brake, and how positive control is obtained 
with but little effort. 

In this case, we have assumed fjhat the total weight of a heavy 
motorcycle, tandem attachment and two heavy riders is GOO pounds. 






































424 


Motorcycles , Side Cars and Cyclecars 


The amount of braking force required at wheel rim is equal to 36 per 
cent of the total weight, or 216 pounds, which represents the ad¬ 
hesion between tire and ground. This is not an extreme case, as the 
modem motorcycle and two large riders would easily weigh 600 
pounds, and a brake must be designed with the abnormal service it 
may be subjected to in mind rather than the average if it is to be 
relied on to cope with the unexpected emergency. 

Almost any rider can exert a back pedal pressure of 100 pounds. 
This is applied at the end of a 6-inch pedal crank, and if the front 
sprocket is 5.4 inches in diameter, a pull of 222 pounds is applied to 
the chain. This is directed to a sprocket having a radius of 2.2 inches, 
which is equivalent to a moment of 488-inch pounds at 1 inch from 
axle center. Owing to the point where the spreader-cam lever end 
bears against the brake shoes being less than 1 inch from axle center, 
we have an effective force of 601 pounds at the end of the lever. The 
difference in length between lever and spreader cam further com¬ 
pounds the pressure, and if we consider all the load concentrated 
against one brake shoe for simplicity, we find that we have an effective 
spreading force of 3,606 pounds at the end of the brake shoe. The 
brake shoe is really a curved lever, so at a point halfway between 
where the cam bears and the fulcrum pin, we find that it is possible 
to exert a pressure of 7,165 pounds. All of this is not available for 
braking, however, because if we consider the coefficient of friction, 
we will have an effective retarding force of 1,075 pounds at the brake 
drum, and this, in turn, is equivalent to a retarding force of 230 
pounds at contact point of wheel tire and road surface, which is at 
14 inches radius, or considerably more than is needed to skid the 
wheel. If a rider is alone, a back pedaling pressure of about 50 
pounds would suffice to lock the wheel. It will be apparent that 
positive control with minimum exertion on part of the rider is possible, 
because the initial force is compounded many times by the simple 
and strong leverage provided. Obviously, the brake force can be 
varied at will and is entirely within the control of the rider. 

Motorcycle Tires. —The single tube tires used on bicycles did not 
have sufficient resistance to perform satisfactorily on motorcycles, and 
also had the grave disadvantage of being difficult to repair. The 
double tube tire which was used to some extent in bicycle practice 


100* / / X\ \ BRAKE SHOE SPREADER CAM 


Design and Construction of Fro V 


425 




























42(j Motorcycles , /Siefe CY//\s* and Cyclecars 

was strengthened and made larger, and adapted for the heavier 
vehicle. This construction consists essentially of two members, an 
outer casing or shoe, and an inner tube that is depended on to retain 
the air. The outer casing is attached to the rim in such a way that it 
may he easily removed to gain access to the inner tube. In event of 
a small puncture, the patch is applied to the inner tube member, and 
the outer casing need not receive attention until a more convenient 
time. A typical outer casing is shown at Fig. 259, A, and it consists 
essentially of a carcass or body composed of layers of Sea Island cotton 
fabric impregnated with rubber. A number of plies of this fabric are 



Fig. 259.—Construction of Motorcycle Tire Outer Casing and Inner 

Tube. 


placed around a suitable iron core with vulcanizing cement between 
each layer, and over these are attached a number of layers of rubber 
composition that forms the tread of the tires. After being built up, 
the assembly is placed in a steam heater and vulcanized or cured until 
it is practically a solid mass. The casing is provided with beads 
around the inside which are intended to fit into channels in the rim. 
When the inner tubes are inflated, the beads will be forced tightly 
into the clincher rim and the tire will be held positively in place. To 
remove the outer casing, it is necessary to deflate the tire. 

The outer or tread portion, which is the part of the tire that is in 
contact with the road surface, is made of exceptionally tough rubber 




















Design and Construction of Frame Parts 


427 


compound which is not apt to depreciate rapidly. The inner tube, 
upon which the resiliency of the tire depends, is composed of practically 
pure rubber, and is therefore adapted for holding air, though the 
material of which it is composed is too soft to possess any strength 
or resistance to abrasion, which must be provided by the outer casings. 
Inner tubes are made in two forms, the continuous or one-piece type, 
which is the same as that so generally used on automobiles, and the 
jointed or butt end form as shown at Fig. 259, B and C. In the 
former, the joint is made by slipping one end of the tube into the 
other, and when the tube is inflated the collar member will be forced 
out tightly against the inner face of the retaining member on the 
other end, and an air-tight joint will be obtained. In the form shown 
at C, the inner tube is a closed end form, and has a tapering end that 
is intended to fit into a corresponding female member at the other. 
The advantage of the jointed inner tube is that it may be removed 
from the wheel without taking that member out of the frame which 
obviously is not possible with a one-piece inner tube. The form shown 
at B, however, is apt to leak to some extent, and if the jointed inner 
tube is used, the form shown at C is preferred. The ends of the tube 
in contact are also apt to chafe and leak. 

Side Car Advantages. —While the tandem attachment is an in¬ 
expensive solution of the passenger-carrying problem, it is not the 
most satisfactory because it is not a really practical means of carrying 
an elderly person or one of the fair sex. The occupant of the tandem 
attachment may throw a machine out of balance by moving around, 
and may seriously interfere with the proper control of the machine 
by the rider, unless very careful and experienced. Then again, it is 
difficult to carry on a conversation between the motorcycle rider and 
the tandem passenger, so this device is not as sociable as the side car. 

The side car is a simple one-wheel framework that may be readily 
clamped to the motorcycle, and which carries a seat of comfortable 
proportions that will provide thorough protection for the passenger. 
When a side car is used, it is imperative to employ a machine of ample 
power, and it is necessary to use a two-speed gear to secure proper 
results when touring. A typical side car attached to a motorcycle is 
shown at Fig. 260, and it will be apparent that the three-wheel vehicle 
thus provided is much more sociable than the tandem attachment, 


428 Motorcycles , Side Cars and Cyclecars 

and also much more comfortable for the passenger. Owing to the 
three-point support, neither the rider nor the passenger need concern 
themselves with maintaining balance, as it is impossible for the 
machine to tip over. It costs but very little more to use the side car 
than it does to ride the machine without this attachment. An im¬ 
portant advantage of the side car construction is that this member 
may be readily removed at such times that the motorcycle alone is 
to be used. 



Fig. 260.—Application of Sidecar to Indian Motorcycle. 


Forms of Side Car. —There are two main types of side cars, the 
rigid and the caster wheel, both forms being shown at Fig. 261. In 
the rigid wheel type at the top of the illustration, the outboard sup¬ 
porting member revolves on a fixed axle and is capable of only a 
rotary movement. In the caster wheel form below it, the outboard 
supporting member is carried in a fork supported by a ball bearing 
steering head so the wheel may turn automatically in the same 



Design and Construction of Frame Parts 429 



Fig 261.—Examples of Rigid and Castor Wheel Side Cars. 


direction as the front wheel of the motorcycle. Experienced users of 
side cars are inclined to favor the rigid type, as it is claimed it is 
simpler, and if properly alined with the motorcycle frame there will 
he but little more wear on the tire than is evidenced in the caster 
wheel type. The form with the movable wheel is easier to steer 





















430 


Motorcycles , Side Cars and Cyclecars 


however, owing to the wheel automatically assuming the angle re¬ 
quired to describe the curve made when turning corners. A side car 
of American design which has attracted some attention on account 
of the novel construction is shown at Fig. 262. This is a flexible form 
in which it is possible for the rider of the motorcycle to lean when 
turning corners just as though the side car was not fitted to the motor¬ 
cycle. The wheel of the side car is carried on an axle spindle sup¬ 
ported by a hinged member from which the lever B extends. This is 
joined with lever A on the other end of the axle by a rod passing 
through the hollow tube forming the rear frame member. Any in¬ 



clination of the motorcycle wheel will produce a corresponding move¬ 
ment of the side car wheel, as lever A controlled by the motorcycle 
will transmit its motion to lever B that controls the side car wheel. 
A locking lever is provided so the wheels will remain vertical, and the 
same effect obtain as with the rigid type side car, if desired. It is 
claimed that the flexible feature makes the machine easier to steer 
than the usual rigid type. The side car frame may be fitted with a 
variety of bodies depending upon the preference of the purchaser, 
ranging from the simple chair form, shown at Figs. 261 and 263, to 
the more expensive coach-built body designs, such as shown at Fig. 
260. 



















431 


Design and Construction of Frame Parts 

Side Car Attachment. —The chassis of a typical side car with 
the body removed is shown at Fig. 264 to outline the method of 
attachment ordinarily followed. Clamps are provided on the motor¬ 
cycle frame at two points, one at the front end of the diagonal tube, 
just below the frame cross bar, and one on the rear fork stay, just a 
little ahead of the motorcycle rear wheel axle. The front end of the 
side car chassis is carried by a curved tube extending from the clamp 
on the frame tube to a similar clamping member at the front end of 
the side car. A yoke at the end of the side car axle attaches to the 
clamp at the rear end of the motorcycle, and a cross bar or brace 



Fig. 263.—Inexpensive Form of Side Car. 


extends from the seat post cluster of the motorcycle to a point on the 
axle of the side car adjacent to the supporting wheel. When the 
clamps are firmly secured a very stiff and rigid frame structure is ob¬ 
tained, and the motorcycle and its side car attachment are prac¬ 
tically one structure. 

Considerable care is needed in fitting a side car, because difficulty 
will be experienced in steering if the wheel of the motorcycle and that 
of the side car are not in proper alinement. This means that not only 
the wheel centers must coincide but that the front end of the side 






432 


Motorcycles , $ ?7/c Cars and Cycle cars 


car wheel must be separated from a similar point on the motorcycle 
wheel by exactly the same amount of space as obtains at the rear 
end. In other words, the side car wheel must be parallel to the 
motorcycle wheel and a line drawn through the axle centers of both 
wheels must also coincide. The method of lining up a side car with a 
straight edge is shown at Fig. 265, A. If the wheel of a side car is 
set ahead of that of the motorcycle or if it is not parallel, steering will 
be very difficult because the wheel will not roll around on an arc of 
a circle but will move with a combined rolling and sliding motion as 
indicated by the dotted lines at Fig. 265, B. 



Fig. 264.—Typical Side Car Chassis With Body Removed, Showing 
Method of Attaching to Standard Motorcycle. 


The diagrams presented at C will show a method of side car opera¬ 
tion recommended by an English authority in order to secure easier 
steering. Even if the side car is perfectly lined up, some difficulty 
may be experienced in steering, though after a rider becomes pro¬ 
ficient, it will not be a difficult matter to control the side car com¬ 
bination satisfactorily. 

Methods of Starting Motorcycles. —The writer will now de¬ 
scribe the common methods of starting motorcycles equipped with 
two-speed gear, as the accepted method of setting the power plant in 
motion in a single-geared machine by means of the pedals is generally 

















Design and Construction of Frame Parts 433 


understood at this time. The starting crank is a satisfactory means, 
if a multiple-cylinder engine is used and the crank can be applied to 
the driving gearing in such a way that the engine will be rotated 
faster than the starting handle. The starting arrangement used on 
the Henderson motorcycle, and illustrated at Fig. 266, is a distinctive 
design, because the handle may be folded out of the way after the 
engine is started. At A, the crank is shown extended for starting the 
motor, while at B the crank handle is shown in place in the clip 


Motorcycle 
Wheel 




Continue at speed from A 
to B & then close the throt¬ 
tle a little to retard the 
bicycle when the side-car 
will swinqround thus help¬ 
ing to take the corner. 



Reduce speed by closing 
the throttle between A & B 
and then accelerate when 
the bicycle will be found to 
run round the side-car. 



Fig. 265.—Diagram Showing Method of Attaching Side Car and of 
Controlling Motorcycle and Side Car Combination. 


attached to the frame that holds it out of the way when the machine 
is in use. 

A large and near view of the Indian kick starter, which is a thor¬ 
oughly practical and simple device, is shown at Fig. 267. A large 
sprocket is mounted on a suitable bearing, and is adapted to be 
oscillated by a starter pedal carrying a suitable pad member against 
which foot pressure may be exerted. The large sprocket is joined to 





















































434 


Motorcycles , Side Cars and Cyclecars 


a much smaller starting sprocket that connects with the engine shaft 
when the pedal is pushed forward and which turns the interior 
mechanism of the engine fast enough to set the power plant in motion. 
It is said that the Indian was the first American motorcycle to depart 
from the conventional pedaling starting system and to introduce the 
foot starter. A forward thrust of the pedal crank engages the ratchet 
drive that connects the small starting sprocket to the engine shaft 
and at the end of the stroke the mechanism releases automatically, 
and permits the crank to return to its normal position. An auto¬ 
matic mechanism provides positive disconnection from the engine 



Fig. 266.—Folding Starting Crank Used on Henderson Four Cylinder 

Motorcycle. 


should a back fire occur. The foot rest on the starting crank is hinged 
and can be folded out of the way when not in operation to allow un¬ 
obstructed use of the foot board. With the foot starter, prompt 
starting is facilitated by priming the cylinders with gasoline, par¬ 
ticularly when the motor is cold. This operation is made easy on 
the Indian machines by placing a small syringe or priming gun in the 
filler opening of the gasoline tank so a small amount of gasoline may 
be drawn out to fill the priming cups on the cylinders. It is said 
that when the engine has become heated it will be easily started 
without priming by one or two forward thrusts of the foot. 

The step-starter used on the Harley-Davidson motorcycle is shown 





Design and Construction oj Frame Parts 435 

in some detail at Fig. 268. The arrangement is such that a pair of 
pedals are provided just as in the usual construction, though no chain 
extends from the pedal crank hanger to the hub. Instead, the engine 
is rotated directly from the pedals through an ingenious ratchet and 
pawl arrangement. The pawl-carrier plate is securely attached to 
the pedal crankshaft, and when that member is rotated forward, the 



Fig. 267.—Outlining Construction of Indian Kick Starter Used on 

Two Speed Models. 


pawls fly out and drop into suitable depressions in the ratchet ring 
which is attached to the first reduction sprocket, and which transmits 
the motion of the crank directly to the small sprocket on the engine 
shaft. The countershaft assembly includes a substantial ball-bearing 
carrying the member on which the first reduction sprocket and the 
rear wheel drive sprocket revolve. As soon as the engine is started, 







Motorcycles , Side Cars and Cyclecars 


43() 



Fig. 268.—Sectional View Showing Construction of Harley-Davidson Kick Starter. 














































































































Design and Construction of Frame Parts 437 


the pawls are released automatically and remain out of engagement 
as long as the ratchet revolves faster than the pawl-carrier plate. 
Another ingenious fitting is a ratchet which works only on back- 
pedaling carried at the other end of the countershaft which is used to 
operate the brake on the rear hub from the pedals when desired. 

Electric Starting and Lighting Systems. —Electric lighting has 
long been recognized as an ideal illuminating system for motorcycles 
as well as motor cars, but it has been somewhat difficult to apply an 
electric lighting system successfully to rigid frame machines. The 
vibration encountered tended to rapid depreciation of the batteries, 
and if attempts were made to utilize current delivered directly from 
a small dynamo driven from the engine, other difficulties were en¬ 
countered. Either the rider was experiencing continual trouble with 
the small round leather belts used in driving the generator or he was 
burning out a bulb, when the motor was suddenly accelerated and 
the generator produced an excess amount of current. If the motor 
was run slowly, the generator would not deliver enough current and 
the lights would burn dimly. In some models of the Indian motor¬ 
cycle, two sets of batteries are furnished and are separately con¬ 
nected to the light. With reasonable precaution, the rider should 
never be without current for lights and electric horn operation. In 
the machines without the electric starter attachment when the lights 
become dim, the battery in service is cut out and the fresh battery 
carried in reserve is connected to the circuit. The batteries do not 
depreciate from vibration on account of being carried by the spring 
frame which insulates them from road shocks. A patented safety 
vent is used which permits the escape of gas from the battery interior, 
but which absolutely prevents the leakage of any of the electrolyte. 
Therefore, in passing over rough roads, or if a machine upsets in a 
fall, there is no weakening of the batteries by loss of liquid. 

The Hendee special model, which is clearly the highest developed 
form of motorcycle ever offered, inasmuch as it not only incorporates 
full equipment including the various necessary accessories but also 
has a two-speed gear and electric self-starter, is shown at Fig. 269. 
On this model, the batteries are so connected that both of them dis¬ 
charge into the electric starting motor to secure the highest amperage 
for turning the engine over as fast as possible. It is said that it is 


EAecWxc VWn ' .Morn Sv^tc.^ 


438 


Motorcycles , Side Cars and Cyclecars 



Fig. 269.—The Hendee Special Motorcycle With Electric Motor Starting Attachment. 



















Design and Construction of Frame Parts 


439 


possible to crank the engine over at the rate of 500 revolutions per 
minute, which is faster than any automobile starter. The nominal 
rating of the combined electric starter and generator is 1.5 horse¬ 
power, but the power actually developed is influenced by the energy 
necessary to start the engine. The starter lias a high over-load 
capacity, and just as soon as the engine begins firing, the starter 
automatically becomes a generator and delivers a current that charges 



the storage battery. The generator is always running while the engine 
is in operation, and an automatic regulator is included in the system 
so that when the batteries are fully charged the surplus electricity 
generated is dissipated. The current consumption of the lighting sys¬ 
tem is approximately two amperes. When the batteries are con¬ 
nected in multiple a current of G volts and 70 amperes is available, 
and when joined in series a current of 12 volts and 35 amperes is 











































































440 Motorcycles , Side Cars and Cyclecars 

available for starting. The batteries are charged at a road speed of 
12 miles per hour on the high gear, and the maximum charging current 
flows to the batteries when the machine is operated at 16 miles per 
hour. 

As shown at Fig. 271, the electric starter is attached to the engine 
crankshaft by a roller chain, and is geared approximately 2 to 1. It 
is said that under ordinary operating conditions, it will start a cold 
motor in 12 or 15 seconds. When a motor is warm but 3 to 5 seconds 


Fig. 271.—Showing Method of Driving Combined Motor-Generator 
of Hendee Special by Roller Chain From Engine Crankshaft. 

will be necessary to start it. As the generator is constantly charging 
the batteries while the engine is running, the possibility of the cells 
becoming discharged is very slight. The current for ignition is de¬ 
rived from the batteries instead of from the usual high tension mag¬ 
neto, and as the batteries are kept fully charged, the main objection 
advanced against battery ignition, that of irregular and uncertain 
current supply, does not apply in this case. A wiring diagram showing 
the connections of the system is presented at Fig. 270. 




Design and Construction of Frame Parts 



441 


Fig. 272.—Parts of Combined Motor-Generator Used on Hendee Special Motorcycle. 






442 * Motorcycles , Side Cars and Cyclccars 

The combination motor-generator used in connection with this sys¬ 
tem has been designed especially for the work, and as may be readily 
ascertained from the views at Fig. 272 it is a very compact and 
effective piece of electrical apparatus. In order to keep the device to 
the proper width, an internal commutator is used which is carried 
inside of the armature member. The brushes are supported by the 
cover plate, and project into the interior of the armature to make 





Fig. 273.—The Automatic Regulator and Control Switch Used in 
Connection With the Indian Electric Starting System. 


suitable connections with the commutator segments placed therein. 
The armature shaft revolves on single row annular ball-bearings, and 
the device thus works with minimum friction. By a simple change 
of the wiring which is accomplished by a manually controlled switch 
at the front end of the tool box, the device may be converted into 
either a dynamo or a motor. The automatic regulator and switch 
member used in connection with the system are shown at Fig. 273. 











443 


Design and Construction of Frame Parts 


When the switch is placed in the starting position, the circuits are 
arranged so that current is drawn from the batteries and directed to 
the starting motor fields. When the switch handle is moved back 
for the running position, the circuits are altered so that the current 
delivered from the generator armature is supplied to the batteries, 
first passing through the automatic regulator, which operates on a 
magnetic principle so that current is being supplied to the batteries 
only when it is of proper value for charging those members. As soon 
as the engine stops rotating, if the switch is left in the charging posi¬ 
tion, the automatic regulator will break contact and prevent the 
batteries discharging back through the windings of the motor- 
dynamo. The automatic regulator also functions and disconnects 
the windings from the batteries at such time that more than the 
charging current is delivered. The low current release portion of the 
automatic regulator also serves to break the circuit, when the power 
plant is running at rates of speed that would produce less than the 
proper amount of current lor charging. 

Motorcycle Control Methods. —When the motorcycle was first 
evolved, there was no attempt made to have the control arranged in 
a convenient manner, as the various levers by which the motor speed 
was varied were placed at any point on the frame that proved con¬ 
venient for the designer in attaching regardless whether it was the 
best position for the person who would operate the machine. At the 
present time, every effort is made to locate the important and fre¬ 
quently manipulated control members where they can be easily 
reached, and very often the arrangement is such that the rider may 
have complete mastery of the machine without removing the hand 
from the handle bars. The control of American motorcycles is con¬ 
siderably simpler than that generally provided on the foreign mounts, 
as the common practice in this country is to regulate the motor speed 
through the medium of twisting grips. Of course, when a two-speed 
gear is used, an auxiliary control member is placed convenient to the 
rider to regulate the gear ratio desired, and on some machines still 
another lever is used to control the free engine clutch. Several of the 
American motorcycles employ grip control of the free engine clutch, 
prominent among which may be mentioned the Schickel, Excelsior 
and Eagle machines. For use in traffic, or operating under conditions 


444 


Motorcycles , Side Cars and Cyclecars 


that necessitate frequent use of the clutch, it is apparent that the 
most convenient method is by the grip because this does not require 
the rider to take his hands from the handle bars which insures positive 
control at a time that it is most needed. The free engine clutch is 
regulated on some machines through the medium of a pedal, and this 
control is very satisfactory on machines equipped with running boards 
to support the rider’s feet and where the usual form of pedaling gear 
is dispensed with. 

The first of the American manufacturers to utilize grip control, to 



Fig. 274.—Handlebars of Indian Motorcycle, Showing Method of 

Motor Control by Twisting Grips. 


regulate engine speed, were the makers of the Indian motorcycle, and 
this method was incorporated in even the earliest models of these 
machines. The method of regulating the motor speed and the con¬ 
struction of the universal joints and rods used in connection with 
practically all Indian models is shown at Fig. 274. The right hand 
grip controls the spark advance and the exhaust valve lift. The 
valves are lifted to relieve the compression and to make it possible to 
turn the engine over easily for starting. The left hand grip is used 
to control the throttle. The twisting movement of the grips is trans¬ 
mitted by means of a flexible shaft running from the grip through the 








Design and Construction of Frame Parts 445 

hollow tube comprising the handle bar to a bearing from which the 
end of the shaft projects. A universal joint attached to this shaft 
transmits its motion to a compound member consisting of one shaft 
telescoping into another, that is secured to the actuating lever at¬ 
tached to the steering head. The reason for using the telescope shaft 
arrangement is that it is necessary to have some flexible connection 
other than the universal joint to permit the handle bars to be turned 
when steering the machine. 



Fig. 275.—Control System of the Rudge Motorcycle, Typical of 

Foreign Practice. 


If one compares this simple and direct control with that shown at 
Fig. 275, which is an illustration of a representative English con¬ 
struction, it will be apparent that the American design is considerably 
neater. Of course, on the single-speed Indian models it is necessary 
to have a lever to actuate the free engine clutch which is caiiied at 
the side of the machine and an auxiliary pedal is provided near the 
footboard to operate the hub brake. On the two-speed machines, a 







446 


Motorcycles , Side Cars and Cycle cars 


lever is provided to shift the positive change speed clutch and a foot- 
controlled member supplied to release the master or free engine 
clutch. In addition to the control members shown at Fig. 275, there 
is another lever which is not illustrated, provided to operate the 
variable speed pulley. The control of the ignition is by a small lever 
at the side of the tank connected with the magneto contact 
breaker. 

The speed of the motor is controlled by the magneto lever and by the 
air and throttle levers mounted on the handle bars and connected to 
the carburetor through the medium of Bowden wire control. At the 
end of each grip, a lever is fulcrumed, one being used to work the front 
wheel brake, which is a fitting prescribed by law abroad, while the 
other is the exhaust valve lifter. On the same bar that carries the 
exhaust valve lifter, a hand lever to control the free engine clutch is 
mounted and as is true of the other elements it is joined to the clutch 
member by the flexible wire connection. From the handle bar 
assembly shown, five of the Bowden wires extend to the various ele¬ 
ments they are intended to control. One goes to the air slide of the 
carburetor, another to the throttle regulating the supply of gas. The 
third member goes to the exhaust valve-lifting arrangement, while 
the fourth and fifth extend to the free engine clutch and the front 
wheel brake respectively. 

Bowden Wire Control. —While the Bowden wire control is used 
on practically all of the foreign motorcycles, and is employed to some 
extent on American machines as well, there is a general lack of under¬ 
standing of its principle of action on the part of the American rider, 
and considerable trouble is experienced from time to time in fitting 
up or making repairs to this system. The Bowden wire mechanism 
consists mainly of two parts, one which, termed “the outer member,” 
is a closely coiled and practically incompressible spiral spring while 
the “inner member” is an inextensible wire cable passing through the 
outer member which acts as a casing. The usual mechanical method 
of transmitting power in other than a straight line in this country is 
by means of universal joints, small bell crank levers and suitable con¬ 
necting rods. The Bowden wire mechanism is considerably simpler 
and is easily fitted. The principal requirement is that the outer 
member or casing shall be anchored to a stop at each end, while the 


Design and Construction of Frame Parts 447 


inner member is attached to an operating lever at one end and to the 
object to be moved at the other. 

A diagram showing the method of operation is shown at Fig. 276, 
and the reader should have no difficulty in understanding the action 
of this control system. A line of Bowden wire mechanism sufficient 
to reach from the point where the object is to be moved to the point 
where the necessary power is to be applied is represented by D D D. 
The outer cable of the mechanism is passed around any intervening 
corners or obstacles. At C C the inner member of the mechanism 
will be seen emerging from the outer case being attached at one end 



Fig. 276.—Diagram Explaining Action of Bowden Wire Mechanism. 


of the actuating lever A and at the other to the object to be moved B. 
The outer member is anchored to fixed abutments G G. If the lever A 
is moved, the motion is at once imparted to the other end. When 
being actuated, the mechanism will exhibit a wriggling movement at 
the curves because the inner member attempts to reach the straight 
line of pull, but is resisted by the outer casing which cannot shorten 
its length inasmuch as it is anchored at both ends. The movement 
should not be restrained, as the mechanism functions best when the 
curves are free. The dotted lines show the lever A in its actuated 
position, and the weight B, or object to be moved, correspondingly 












































448 


Motorcycles , Side Cars and Cyclecars 


raised. E E are adjustable screws or stops, the screwing out of which 
is equivalent to lengthening the outer member, and are held in position 
by the lock nuts F F. 

Various examples of the levers used in connection with Bowden 
wire mechanism are shown at Fig. 277. The hand lever with ratchet 
retaining lever shown at A is widely used for clutch actuation, brake 
application and lifting the exhaust valves. The assembly shown at B 
consists of two levers carried above the clamp, and a lifting lever 
below it. One of the upper members may be used to control the spark 



Fig. 277.—Showing Various Forms of Levers Used in Connection 

With Bowden Wire Mechanism. 


time and the other connected to the throttle, or both may be used to 
regulate the carburetor. The handle at the lower part of the assembly 
may be connected to brake, clutch, or exhaust valve release. A group 
of three control levers, each being plainly marked to show the func¬ 
tions performed, designed for handle bar attachment is shown at C. 
The pedal at D is adapted for brake actuation. 

The Bowden wire control is also sold in connection with complete 
control devices, two popular fittings being outlined at Fig. 278. At A 
a front wheel brake assembly is shown. The contact blocks which 










Fig. 278.—Showing Practical Application of Bowden Wire Mechanism 
for Controlling Front Wheel Brake, Auxiliary Air Intake and 
Magneto. 

jThe following hints on fitting the Bowden wire mechanism, given 
by the makers, will undoubtedly be found of value by riders and 
repair men who are not thoroughly familiar with the application or 
maintenance of this system of control. 


lJesign and Construction of Frame Parts 449 

bear against the wheel rim are carried by a U-shaped member that is 
held at its lower portion by clips attached to the fork sides. The 
upper portion may be guided by any suitable bracket and is connected 
with a hand lever intended to be attached to the handle bar by a 
length of the Bowden wire mechanism. An auxiliary air fitting and 
suitable controlling means, are shown at B, while the usual method of 
rigging up to a magneto contact breaker is shown at C. 


ti . 

L - 



























450 


Motorcycles , Hide uars ana wyuecurs 


It is important that the inner member of the mechanism should be 
soldered before it is cut, as it is composed of a number of fine strands 
■ which are liable to become untwisted unless this precaution is taken. 
With the smaller sizes, up to No. 3, a pair of pliers or a spoke-cutting 
machine will suffice for cutting, but larger sizes will require a file or 
cold chisel to sever the strands. 

The brass nipple supplied for the purpose should be carefully at¬ 
tached to the end of the inner member. A good method of effecting 
tins is as follows: The wire, after being soldered ana cut, should be 
passed through the nipple, the end then being nipped fi<2t for about 
1 /16 inch. Tins will prevent it drawing out again during the 1 process 
of soldering the wire and nipple together, which should be doT® in 
combination with a non-corrosive soldering fluid (on no accoipt 
should killed spirit be used), care being taken that the soldered joint 
extends the full length of the nipple. The nipple should then be hel<d 
in the vise, and the wire burred over and finished off with a blob ol 
solder. It will then be found impossible to remove the nipple by any 
fair means. 

For the varieties of the mechanism known as Bowdensilver, 
Bowdenbrass, and Bowdenite, special metal caps are provided for 
encasing the ends. These serve the purpose of finishing the ends off 
neatly, and, in the case of Bowdensilver and Bowdenbrass, prevent 
the protecting cover uncoiling. 

When a single-pull lever is used, it is necessary to have a spring at 
the opposite end of the wire to which the lever is fixed, in order to 
ensure prompt recovery. This spring may be made either to pull 
the inner member back through the outer member, after pressure has 
been relieved from the operating lever, or it may be inserted between 
the stop holding the outer member and the end of the inner member, 
in which case, of course, it will be in compression. In the latter case, 
it will generally be found that the simplest method of fixing is to fit 
the device up minus the spring, and to wind the spring on afterward, 
as one puts a key on a split ring. But when a double-pull lever is 
used, a spring is not necessary, as the separate mechanisms so balance 
each other that while the lever is pulling on in one direction it is 
pulling off in the other. 

Care should be taken that the inner member, on leaving the stop 


Design and Construction of Frame Parts 451 


in which the outer member terminates, should be kept in an abso¬ 
lutely straight line, as should it be otherwise, it will rub on the edge 
of the stop, and be gradually worn away in consequence. 

The inner member should be thoroughly smeared with motor grease 
or vaseline before being passed through the outer member. 


CHAPTER VII. 


CONSTRUCTIONAL FEATURES OF CYCLECARS. 

Advantages of Cyclecars—Influence of Motorcycle Design—Three Wheel 
or Tri-car Forms—Typical True Cyclecars—Seating Arrangements— 
Advantages of Narrow Tread—Cyclecar Chassis Design—Cyclecar 
Power Plants—Cyclecar Change Speed Gears—Power Transmission 
Methods—Steering Arrangements—Methods of Springing—Cyclecar 
Control Methods. 

Considerable interest obtains at the present time in a new form of 
motor vehicle, known as the “cyclecar.” These small vehicles are of 
two general types, both of which will, undoubtedly, receive wide 
application. Some of the vehicles that are termed “cyclecars” are 
in reality miniature automobiles, and do not conform to the precise 
definition generally accepted for cyclecars. While engineers and de¬ 
signers disagree upon the characteristics of the new vehicle, it is 
generally Relieved that the term “cyclecar” should be applied to light 
four-wheeled vehicles using motorcycle parts in their construction. 

The true cyclecar offers a number of features that will enable it to 
fill a distinct field that cannot be catered to by the builders of either 
low-priced automobiles or motorcycles. In the cyclecar there is a lack 
of complication in the mechanism, a low center of gravity making for 
stability is obtained, a streamline body construction, especially in the 
tandem seating arrangement, is possible which reduces wind resistance 
to a minimum. While at the present time there are no reliable sta¬ 
tistics regarding the cost of maintenance in this country, if one reasons 
from experience with a motorcycle and sidecar combination, it is 
possible to arrive at the conclusion that two persons can travel over 
average highways at a total cost for fuel and tires of not more than 
two cents per mile, whereas it would cost at least three times this sum 
to cover the same distance with the lightest form of miniature motor¬ 
car. Several designs are being produced at the present time in this 

452 


Constructional Features of Cyclecars 


453 


country that will sell at prices ranging from $350 to $450, and it would 
seem reasonable to assume that many people could afford to purchase 
a cyclecar who would not be interested in a small automobile on 
account of its higher initial cost and greater maintenance expense, 
and yet who would not favor the motorcycle or sidecar combination 
at the same cost, on account of the greater protection and easier con¬ 
trol of the cyclecar. 



Fig. 279.—Chassis of Motorcycle With Forecar Attachment, the 

Original Form of Cyclecar. 


The greatest advantage of the cyclecar must always be its wonderful 
economy. The simpler forms do not weigh any more than a combina¬ 
tion of a motorcycle and sidecar, and the true cyclecars should cost 
but little more to operate than a motorcycle. One of the chief items 
of expense in even the smallest of the automobiles is tires, and it is 
evident that where engines of comparatively low power are used 
there will be no necessity for the sizes of tires designed to support 





454 


Motorcycles , Side Cars and Cyclecars 



heavier and more powerful vehicles of the light car pattern. The 
small size of the power plant also insures that minimum gasoline and 
oil will be consumed. The cyclecar may be easily handled, as for the 
most part the control is by regular automobile methods, and at the 
same time the small size enables one to use a small shed instead of 
the special garage necessary with the larger car. The cyclecar has 
attained a great popularity in this country as well as abroad, and 
whereas there were not more than eight or ten types of cyclecars 


Fig. 280.—The Morgan, One of the Best Known of English Three 

Wheelers in Racing Trim. 

available a year ago, and these all of foreign manufacture, there are, 
at the present time, over three hundred makers of cyclecars in the 
United States, England and France. 

The cyclecar appeals to the owner of an automobile as an auxiliary, 
as its simple and light construction and economy enables the motorist 
to use this in.running around as in doing errands, making short local 
and suburban trips and, in fact, using it at all times that it would not 












Constructional Features of Cyclecars 


4 55 


be worth while to start and operate the larger car. The motorcyclist 
will be interested in the cyclecar, because, for the most part, these 
vehicles incorporate features with which he is already familiar. The 
four-wheel form is an excellent means of taking two passengers about 
with more comfort, for the driver, than would be obtained with either 
motorcycle and tandem attachment or a motorcycle-sidecar combina¬ 
tion. Apart from those who are already interested in either auto¬ 
mob iling or motorcycling, there are thousands of conservative people, 
especially middle aged artisans or professional men of all classes, who 



Fie 281.—The Auto-Carrier’s Two Passenger Three Wheeled Cyclecar 

Model. 


do not take kindly to the motorcycle, and yet who cannot afford the 
upkeep of even the cheapest of American runabouts built on con¬ 
ventional automobile lines. The economy, simplicity, ease of handling 
and storage and other advantages of the cyclecar will appeal to these 
as a motorcycle or an automobile never could. 

The definition of the cyclecar was decided on the 14th of December, 
1912, at a meeting of the International Federation of Motorcycle 
Clubs, and the classification given at this meeting is said to hold good 




456 


Motorcycles , Side Cars and Cycle cars 


in England, Canada, the United States, France, Holland, Belgium, 
Italy, Austria and Germany. Cyclecars are divided into two classes, 
a large and a small. The maximum weight permissible in the large 
class is 784 pounds, the maximum engine capacity to be 1,100 cubic 
centimeters (66+ cubic inches) and the minimum tire size 60 milli¬ 
meters (approximately 2.25 inches). In the small class, the minimum 
weight shall be 330 pounds, the maximum 660 pounds. The maxi¬ 
mum engine capacity is to be 750 cubic centimeters (45+ cubic 
inches) and the minimum tire size 55 millimeters. All machines are 
to have a clutch and change-speed gearing, and even those forms in 
which a clutch action is obtained by slipping the belts and changes 
of speed by varying pulley diameter are considered as complying with 
this regulation. This definition is by no means permanent. 

Influence of Motorcycle Design. —Before the side-car forms 
of passenger carrying motorcycles were evolved, a two-wheel 
fore carriage replaced the usual front fork assembly, the whole 
forming a three-wheel conveyance that was very speedy and practical. 
The tricar is considerably easier to handle than the average sidecar 
combination, as the two front wheels were carried by an automobile 
type axle, and were controlled by the regulation Ackerman steering 
gear, universally applied on automobiles. The chassis of a typical 
three wheeler, of which a motorcycle serves as a basis, designed for 
commercial work, with the body removed to show arrangement of 
parts is clearly outlined at Fig. 279. There is no reason why standard 
motorcycle components could not be incorporated as a four-wheel 
vehicle, and the true cyclecar may be considered a four-wheel motor¬ 
cycle, inasmuch as in practically all of the successful types, a regular 
two-cylinder air-cooled power plant of the Y-type is used which drives 
through leather V-belt to wheels but slightly heavier than those used 
on the powerful motorcycle. Designers of cyclecars have profited 
considerably from the experience of motorcycle designers because in 
that vehicle it is necessary to obtain maximum strength, reliability 
and endurance by very careful selection of materials and proportioning 
of parts that were strong and yet not bulky. It is not strange, there¬ 
fore, that in seeking to evolve vehicles capable of being sold at a low 
price cyclecar designers should avail themselves of the knowledge 
gained in building motorcycles and use some of the principles that 


Constructional Features of Cyclecars 


457 



Fig. 282.—Side Elevation and Plan Views of the Auto-Carriers’ Three 
Wheeled Chassis, Showing Unconventional Disposition of the 
Power Plant. 


have been tried out on the two-wheeled vehicles and proven suc¬ 
cessful. 

Those who are opposed to the cyclecar, call it a “hybrid” con¬ 
struction in which both automobile and motorcycle practice has been 
combined. This is true, as in most forms of cyclecars one will find 
features of both classes of vehicles. This is not anything to discredit 
the cyclecar, however, as the first automobiles were hybrids in which 
endeavor was made to propel horse-drawn vehicles by self-contained 
power, and, in fact, it is not unjust to say that the motorcycle of to-day 
is just as much of a hybrid as the cyclecar, because it includes many 
features of the bicycle with just as many taken from automobile 






















































































































458 Motorcycles , Side Cars and Cyclecars 

practice. The influence of motorcycle design on cyclecar construction 
lias been a favorable one, inasmuch as it permitted the designer to 
evolve a new type of vehicle that, while light and simple, has ample 
power and sufficient strength to be enduring. 

Three=Wheel or Tricar Forms. —The tricar construction or the 
three-wheeler has not been abandoned by any means abroad as is 
the case in this country. Many efficient and presumably satisfactory 
three-wheelers are in use in Europe. The reason given for the aban¬ 
donment of the three-wheel construction, in pleasure vehicles, in this 



Fig. 283.—Three Wheel Cyclecar of German Design With Combined 
Directive and Tractive Member for Front Support. 


country, was that the character of our highways did not favor a form 
of vehicle in which the two front wheels would follow the wagon track 
while the rear one would travel between them on that portion of the 
road traversed by the horses’ feet. On soft roads such as were common 
in America several years ago before the widespread and almost uni¬ 
versal use of the automobile promoted a general appreciation of the 
advantages of better highways, the objections to the three-wheel form 
were certainly based on practical experience and not mere theory. 











Constructional Features of Cyclecars 


459 


The conditions abroad are much more favorable to tricar develop¬ 
ment because the highways are uniformly good, and are not apt to 
be rutty or have soft surfaces as in this country. Another thing that 
detracted from the popularity of the tricar form was its unconven¬ 
tional appearance as these did not seem to be either motorcycles or 
automobiles. This objection does not apply to the four-wheel cycle- 
cars, because in most designs these resemble miniature automobiles 
or to the sidecar-motorcycle combination. 

A typical tricar of English manufacture which has been used very 
widely in that country is shown at Fig. 280. This is known as the 
Morgan and is unconventional in several respects. One of these is 
in the method of carrying the power plant directly at the front of the 
chassis and ahead of the front axle. The drive from the engine is by 
a shaft to a countershaft through the medium of a pair of bevel gears, 
and on this countershaft are mounted positive clutches adapted to 
engage either of two driving chains which run to the single rear wheel, 
which serves as a traction member. Another popular English three- 
wheeler, known as the auto-carrier, is shown in the two-passenger 
form at Fig. 281. The side elevation and plan view at Fig. 282 show 
clearly the disposition and arrangement of the power plant and other 
components. The engine in this case is carried beneath the operator’s 
seat and drives the rear wheels through a simple chain. A clutch and 
two-speed gear is incorporated in the rear hub. The design of the 
chassis presented is such that the space at the front end may be 
' utilized to advantage for carrying parcels as there is sufficient room 
for a large carrying case. 

An unconventional design of German manufacture that has been 
copied in this country but which has never been popular is shown at 
Fig. 283. This three-wheeler differs from the others described, in 
that the single front wheel serves both for steering and driving the 
vehicle. The two rear wheels revolve on a dead axle as in horse-drawn 
wagon construction, and are employed only as load-carrying members, 
though brakes are applied to drums carried by the wheel hubs. The 
engine is a two-cylinder four-cycle air-cooled form with external fly¬ 
wheel. It drives the front wheel through the medium of a large 
sprocket attached to the front hub. A clutch is interposed which is 
controlled by rotating the spade handle at the end of the steering 


Motorcycles , Side Cars and Cyclecars 


400 



Fig. 284.—The Bedelia Cyclecar, the Original Four Wheeled Form Fitted Up for Racing. 








Constructional Features of Cyclecars 461 

tiller bar. If the handle is moved in one direction, the low-speed gear 
is engaged; if turned in the other, the high-speed is brought into 
engagement. Three control levers for the motor speed are carried 
just above the handle on the tiller bar, one of which is used to control 
the magneto, the other two to regulate the carburetor. About half 
way up the steering tiller or control bar, an oil tank is mounted to 
which a suitable pump is attached by which oil may be directed to 
the engine crank-case. While it would seem difficult to handle this 
combination, owing to the great amount of weight carried by the 
front wheel, the vehicle is said to steer easily, and to give very good 
service under severe operating conditions. 

Typical True Cyclecar Forms. —The original cyclecar was de¬ 
signed to take the place of the motorcycle and sidecar combination 
that has been very popular in Europe, even more so than in this 
country. This as shown at Figs. 284 and 285, is known as the 
“Bedelia,” and a model was built by M. Barbeau, of Paris, France, 
as early as 1910. This was a very small automobile driven by a 
motorcycle power plant. Its weight was less than 400 pounds, and 
it had a tread of 36 inches. The wheel-base was 100 inches, and, as 
it was very low, the passengers were carried very comfortably. It 
was made to accommodate two persons, the passenger being seated 
in front, while the driver sits over the rear axle. On the modern 
forms, the twin-cylinder motorcycle engine of about 8 horse-power 
is placed just behind the front axle, and drives a countershaft which 
is crosswise of the chassis under the passenger's seat by a roller chain. 
Pulleys of the motorcycle type suitable to take the regular V-belt 
are attached to the ends of the countershaft, and these impart motion 
to the large belt pulleys on the rear wheels by means of motorcycle 
belts. 

An ingenious clutch action is obtained by drawing the rear axle 
forward when it is desired to stop the car, as this makes the belt run 
loose and enables the motor to turn without driving the wheels. A 
further movement of the hand lever brings the rear axle forward far 
enough so the belt pulleys engage fixed brake blocks or shoes which 
arrest motion of the wheels. The steering is by means of a wire-spoke 
hand wheel which turns the whole front axle through a drum on the 
steering shaft and a steel cable connection through pulleys. The 


4f>2 


Motorcycles , Side Cars and, Cyclecars 




Fig. 285.—Two of the Regular Bedelia Models. Two Passenger 
Touring Type Above, Commercial or Light Delivery Design 
Below. 

axle is hung at a central point in a steering head very similar to that 
of the motorcycle. 

The first public appearance of the car was in a road race over a 
course 138 miles long, and this small vehicle surprised the public, and 
more so its inventor, by averaging 38 miles an hour the entire distance. 
The same car attained a speed of 55 miles per hour on a track. This 
resulted in a large demand for these cyclecars, and induced many 
manufacturers to enter the field. 

A number of other designs that are patterned very closely after 
the Bedelia have been contrived. One of these, known as the “Auto- 
mobilette,” is shown at Fig. 286, and it will be evident that con¬ 
siderable space is available under the hood for housing a much more 












Constructional Features of Cyclecars 


463 


pretentious power plant than the small engine used to drive the 
vehicle. This employs side-by-side seating. Practically the entire 
passenger weight is carried over the rear axle. The method of con¬ 
trol is just the same as that used in the Bedelia, as the entire rear 
axle is moved to obtain a clutching action through varying the tension 
of the driving belt. The Super, another French cyclecar, is shown 
at Fig. 287. This design also involves the movable rear axle, and, 
with the exception of the seating arrangement, resembles the original 
Bedelia design very closely. The tandem seating arrangement is 
followed, but the positions are reversed from the practice established 



Fig. 286.—The Automobilette, a French Racing Cyclecar With Side 

by Side Seating Arrangement. 


by the Bedelia. The driver occupies the front seat and the passenger 
the rear. A number of cyclecar designs showing the possible range 
from the three-wheel racing monocar to the form following very 
closely the lines of the average small automobile are illustrated at 
Fig. 288. 

The tendency of some American designers is to follow closely estab¬ 
lished automobile practice in some forms except as relates to power 
and size of components. Other constructors believe that the cyclecar 
should be designed especially for the work it is to do and along dis- 















464 


Motorcycles , Side Cars and Cyclecars 


tinctive lines that depart from conventional automobile practice. 
Two American cyclecars, shown at Fig. 289, are modified from current 
automobile practice. The one in the upper part of the illustration 
is an underslung construction in which the axles are mounted above 
the frame sides, while the one shown below it has the frame sup¬ 
ported above the axles as in usual forms of motorcars. The cyclecar 
designs at Fig. 290 show a radical departure from the usual auto¬ 
mobile, and, at the same time, do not ape the Bedelia as closely as 
do many of the foreign cars. The power plant is mounted in a 
different way, i. e., the crankshaft runs parallel with the frame side 



Fig. 287.—The Super, a French Cyclecar Patterned After the Popular 
Bedelia Model Except That Driver Occupies Front Seat. 


members, and the variable speed feature is obtained by a friction 
change-speed gearing. Drive to the rear wheels is by short belt in¬ 
stead of the longer members used on the original cyclecar. The model 
shown at the top is a two-passenger touring form, while the light 
delivery type is clearly depicted below it. Two cyclecars built on 
simple lines are shown at Fig. 291. In both of these, the long driving 
belts that are a feature of the original, or Bedelia type, are retained, 
but the drive is through a friction transmission in both cases, which 
provides a combined clutching and variable speed feature. While 
tandem seating is employed, the driver is seated at the front and the 

























Constructional Features of Cyelecars 


465 



Fig. 288.—Typical Cyclecar Designs That Have Proven Practical. 
















































466 Motorcycles , Side Cars and Cyclecars 

passenger at the rear, which seems to be the general trend in this 
country. 

Seating Arrangement.—Some designers who do not favor the 
tandem seating that is a feature of many cyclecars, have endeavored 
to apply the side-by-side seating that is the rule in automobiles. 
While it is not difficult to provide a seat of ample size to take two and 
even three people in a body of standard width adapted for the 56-inch 
tread chassis, it is somewhat of a problem to obtain side-by-side seat- 



Fig. 289.—Examples of American Cyclecars Following Automobile 
Lines on a Smaller Scale. Above, the Lavigne, Below, Detroit 
Speedster. 


ing with the narrow tread that prevails on most cyclecars. A 36-inch 
tread does not permit of a body much wider than 26 or 28 inches, 
and the seats must be narrow unless the body is allowed to overhang 
the wheels or project on the sides. The arrangement shown at Fig. 
292 is one method of carrying two people without unduly increasing 
the body width. The tandem seating that has been such a feature 
of the Bedelia cyclecar is shown at Fig. 293. In this, the passenger 
is carried ahead of the operator which is reverse to the general practice 
in England or this country. There is one disadvantage of moment 



















































Constructional Features of Cyclecars 


4 f>7 


in using wide bodies, and that is the factor of air resistance, which 
means that more power will be consumed than where there is less 
exposed area as when one passenger is carried behind the other. As 
has been previously explained, the factor of air resistance is an im¬ 
portant one that cannot be neglected, especially at speeds over thirty 
miles per hour. The seating arrangement that permits of minimum 
air resistance is the best for the simple form of cyclecar, because the 



Fig. 290.—Two Models of the Scripps-Booth Cyclecar. Touring Model 

at Top, Below, Commercial Type. 


power plant may be of lower capacity to attain the same speed a 
larger engine would provide in a wide body design. 

Advantages of Narrow Tread.—The first Bedelia type cars built 
in England were patterned very closely after the original design, but 
very soon the demand was for more artistic body designs and more 
luxury, so that at the present time many of the vehicles produced in 





































































Motorcycles , Side Cars and Cyclecars 



England that are called cyclecars are really small automobiles that 
sell as high as $1,000, although they still retain the narrow tread, 
which is considered a feature of decided advantage, inasmuch as it 
permits the cyclecar to be housed in a small shed, and avoids the 
necessity of special full-size garage facilities. It is claimed that the 
36-inch tread construction is not suitable for American roads, because 
it will not track with other vehicles which use the standard tread of 
56 inches. It is, of course, admitted that the main highways of Conti¬ 
nental Europe, and of England, have exceptionally good road surfaces. 




Fig. 291.—Two American Cyclecar Designs Employing Long V Belt 
Drive. At Top, Malcolm, Below, the Imp. 

In France, however, where the first cyclecars were produced, there 
are plenty of byways with ruts worn by traffic, which, while perhaps 
not as bad as the majority of country roads in America, offered ample 
opportunity to test the practicability of the narrow-tread cyclecar. 
As there has been no change in the tread of the Bedelia in 3 or 4 years, 
and as the narrow tread has been continued by other French and 
English designers, it is apparent that the narrow tread gave satis¬ 
factory service. The usual width of the road ruts in America is 7 or 









































Constructional features oj Cyclecars 


4G9 



Fig. 292.—Plan View of the Pioneer Cyclecar, Showing Side by Side 

Arrangement of Seats. 

8 inches and they are 56 inches apart, which means that there is 
approximately a space of 42 inches between the wheel tracks, which 
should be ample to allow a vehicle of 36-inch tread to pass between 
them. 

Cyclecar Chassis Design. —In vehicles of the light car or auto¬ 
mobile type, there is not much difference in the general arrangement 
of parts of the chassis than that prevailing in the larger vehicles. 
This is clearly outlined by the two chassis types shown at Fig. 295.. 







&M.' - : i A' 1 


HBiwMPil 


Fig. 293,—Top View of the Bedelia Cyclecar, Showing Tandem 

Seating Arrangement. 
















470 


Motorcycles , Side Cars and Cyclecars 


Anyone familiar with automobile practice can see that in the placing 
there is very little difference except for the size of the parts. The 
location of the power plant, change-speed gearing, and method of final 
drive to the live rear axle, is the same. The motor is placed at the 
front of the chassis. In one case, the gear box is carried about midway 
between the wheels, while in the other it forms part of the unit power 
plant. The final drive is by means of propeller shaft to bevel gearing 
in the rear axle. A true cyclecar chassis is shown at Fig. 296. In 
this, the power plant which is a twin-cylinder air-cooled motor rated 
at 12 horse-power drives a friction disc through a shaft connection. 
A friction wheel is mounted on the cross shaft, and is adapted to be 



Fig. 294.—Diagrams Showing Desirability of Narrow Tread in Per¬ 
mitting Cyclecar to Run Between Ruts Made by Vehicles With 
Standard Tread. 


moved back and forth across the face of the friction disc. The final 
drive is by means of belts to the rear wheels revolving on the fixed 
rear axle. The chassis at Fig. 297 does not differ essentially in prin¬ 
ciple from that previously described, except that a four-cylinder 
water-cooled motor is used and final drive to the rear wheels is by 
roller chains. 

Cyclecar Power Plants. —The type of power plant utilized in 
cyclecar propulsion depends entirely upon the nature of the vehicle. 
For instance, the simple type or true cyclecars use motors patterned 
after forms that have received general application in motorcycle 
sendee, while the light cars or those which follow automobile practice 
more closely employ water-cooled motors, usually of the four-cylinder 



































Construction at Features of Cyclecars 


471 



Fig. 295.—Two Methods of Chassis Suspension Used in Cyclecars and Light Cars. At Top, Chassis 

Supported Above the Axles, Below, the Lavigne Underslung Design. 













































































472 


Motorcycles , Side Cars and Cyclecars 


■ 

' -: 7 i \• 

b '-"I ;)'U?v r'4 r 



Fria L ion 

/ Oisc 


Air Coo 

Motor 


Friction 


Fig. 296.-—Chassis of the Merz Cyclecar, 
Showing Arrangement of Parts and 
Substantial, Simple Design. 


type. The engine shown 
at Figs. 299 to 301, in¬ 
clusive, is a two-cylinder 
form that will develop 
about 12 horse-power at 
a speed of 2,500 revolu¬ 
tions per minute, and 
follows motor-bicycle 
practice very closely, in 
that it employs two air¬ 
cooled cylinders, disposed 
one each side of the 
crank-case center line at 
an angle of about 223 ^ 
degrees with the crank¬ 
case center line, or one 
might say that the two 
cylinders had an included 
angle of 45 degrees. As 
is common with the light 
engines used in motor¬ 
cycles, the inlet valves 
are mounted above the 
exhaust valves, and are 
operated by tappet rods 
and rocker arms, whereas 
the exhaust-valve stems 
are actuated directly by 
the usual form of push 
rods. In order to make 
for steady running, the 
motor is provided with 
an outside fly-wheel in 
addition to the balancing 
members mounted inside 
of the enclosed crank¬ 
case.. To insure adequate 



























473 


Constructional Features of Cyclecars 



Wheel 

Speed 

Changing 
L ever 


iator 

Motor 


Drive 
Cho'm 




Fig. 297.—Plan View of the Trumbull Light Car Chassis, Showing 
Friction Change Speed Gearing and Double Side Chain Drive. 












474 


Motorcycles , Side Cars and Cyclecars 


cooling when the vehicle is standing still, a two-blade fan directs 
a current of air against the cylinders. Ignition is by high tension 
magneto and the weight of the entire power plant, including magneto, 
carburetor, external fly-wheel, and cooling fan, is but 100 pounds. 
This type of motor is efficient, fairly well balanced, and powerful 
enough for the simple form of cyclecar that does not weigh over 500 
or 600 pounds. It will propel such vehicles at speeds up to 50 miles 
per hour without difficulty, and is very economical of fuel, inasmuch 



Fig. 298.—Showing Method of Placing 90 Degree Twin Motor 
Employed in Bedelia Racing Cyclecars. Note Direct Drive From 
Variable Pulleys on Engine Crankshaft. 

as one gallon of gasoline will serve for 50 miles, if the carburetor is 
properly adjusted. 

When the simple motorcycle forms of two-cylincler engines are used, 
in order to facilitate starting, decompressors are added to the cylinders 
which relieves the high compression, and thus makes it easier to crank 
the motor. These decompressors operate on a different principle than 
those ordinarily used in motorcycle practice where the exhaust valve 
is raised and a portion of the charge allowed to escape through it. 










Constructional Features of ( yclecars 


475 



-Front View of the Spacke De Luxe Twin Motor for Cycle- 
ars . This Power Plant Follows Motorcycle Practice, 

















476 


Motorcycles, Side Cars and Cyclecars 



V 


C 


CD: 






O <-M 
o si 

S“ 

V-I 

St3 



— 1 fit 



















Constructional Features of Cyclecars 


477 



Fig. 301.—Diagram Giving Principal Dimensions of Spacke De Luxe 

Cyclecar Motor. 


They consist of a chamber screwed to the cylinder head, having a 
valve at the lower portion that may be opened by moving a suitable 
cam lever that is in contact with the upper part of the valve stem. 
These act to increase the compression space, and provide an auxiliary 
chamber that fills with gas. This is not wasted as it is drawn back 
into the cylinder on the next intake stroke. 

The motors intended for cyclecar propulsion are provided with two 
methods of drive. In the form shown at Fig. 300, A, the motor is 
intended to be placed in the frame of a cyclecar in just the same 
manner as it is arranged in the motorcycle, i. e., one cylinder behind 
the other. In this case, a sprocket for roller chain drive is attached 
to the fly-wheel. If the motor is to be placed transversely in the 
frame, as when friction drive is employed, a slip joint is provided in 


























































































































































478 Motorcycles , Side Cars and Cyclecars 

which a squared end of the driving shaft will fit. This permits of a 
back and forth movement of the shaft and yet insures that the drive 
member must turn positively. The dimensions of a typical American 
cyclecar motor showing the compactness and accessibility of this very 
efficient power plant are given at Fig. 301. Two-cylinder motors of 
the V-type used abroad are often of the water-cooled form as shown 
at Fig. 302. A two-cylinder opposed motor of the air-cooled form 
adapted for cyclecar and light car propulsion is shown at Fig. 303, 
and the smooth running qualities of this type of power plant should 
make it very popular when its good features are properly appreciated. 


In the cyclecars of the automobile type, the usual form of four- 



Fig. 302.—Twin Cylinder Cyclecar Motor of Precision (English) 
Design With Water Cooled Cylinders. 




Constructional Features of Cyclecars 


470 



Fig. 303.—Double Cylinder Opposed Air Cooled Motor Adapted for 

Cyclecar Propulsion. 



Fig. 304.—Sectional View of Typical Four Cylinder Water Cooled 

Power Plant for Light Cars. 














































































































480 


Motorcycles , Side Cars and Cyclecars 

cylinder water-cooled motor such as shown at Fig. 304 may be used, 
but the writer does not propose to consider this form to any extent 
because they are practically automobile power plants and follow the 
rules of practice established by automobile designers rather than 
motorcycle principles which we aim to describe in this treatise. Com¬ 
plete exposition of the automobile in all its forms will be found in 
“The Modern Gasoline Automobile,” another of the writer’s works. 



Fig. 305.—Spacke Geared Up Starting Crank to Facilitate Prompt 

Starting of Twin Cylinder V Motors. 


As considerable difficulty is obtained in cranking the V-type of 
motor sufficiently fast to induce prompt starting when the starting 
crank was applied directly to the motor crankshaft, the geared-up 
construction, shown at Fig. 305, has been devised to turn the engine 
over at a high rate of speed without revolving the starting handle 
unduly fast. Another good feature of the angular teeth is that the 































































Constructional Features of Cyclecars 


481 


pinion will engage automatically when the crank or starting handle 
is turned and will release promptly as soon as the motor starts. 

Cyclecar Change=Speed Gears. —A form of change-speed gearing 
that has been widely applied on cyclecars, because of its simplicity 
and cheapness, as well as ease of operation, is shown at Fig. 306. In 
devices of this form, one is enabled to obtain a combined clutching 
and change-speed action without much complication. The engine 
shaft is coupled to a driving disc of aluminum or cast iron which may 
be moved back and forth to contact with a driven wheel on a cross 
shaft. The drive is by frictional contact between the two discs, the 



Fig. 306.—Arrangement of Friction Change Speed Gearing Used in 

Many Cyclecars. 


clutching action is obtained by bringing the discs together while the 
speed-changing function depends on the position of the driven disc 
to the center of the driving member. The nearer the center the driven 
disc is placed, the slower the speed of that member because it is con¬ 
tacting with a smaller circle on the driving face of the disc turned by 
the engine. If the friction driven disc is moved to one side of center, 
a reverse motion will be obtained. Just the other side of center from 
the reverse will be the slow speed position. The speed then increases 
as the driven disc is moved toward the edge of the driver. 

In some forms, the driving disc is held pressed in engagement with 
the driven member by a coil spring, and the clutching action is re- 




















482 Motorcycles , Side Cars and Cyclecars 

leased by compressing the spring to relieve the pressure existing 
between the two transmission members. This is true of the form 
shown at Fig. 306, as the connection between the pedal to release 
the friction and the shifting member that compresses the spring are 
clearly shown. In order to provide a greater pressure than that 
afforded by the spring under conditions where the resistance is severe, 
an additional pedal is provided which is adapted to augment the 

pressure produced b y 
the spring and thus ob¬ 
tain greater adhesion 
between the transmission 
parts. The driven disc, 
which is adapted to be 
move d laterally on a 
cross shaft, is faced with 
strawboard fiber which 
has a greater amount of 
adhesion with a cast iron 
driving member than any 
other material, and which 
is also enduring. Those 
who do not favor the 
friction type of trans¬ 
mission contend that it 
is very inefficient because 
there is considerable 
power loss due to slipping. 
While this is true of the 
extreme low speed and 
reverse position, the los¬ 
ses on the speed most used which is the range between the letters B 
and C in the illustration Fig. 307 is from 8 to 16 per cent. When on 
the highest speed position, or at B, there is but 8 per cent slip. 

A simple form of change-speed gearing in which two forward speeds 
are provided but no reverse which is used on the Morgan three-wheel 
cyclecar is shown at Fig. 308. The drive is by shaft from the engine 
located at the extreme front end of the vehicle to a bevel pinion that 



Fig. 307.—Diagram Illustrating Slip in Fric¬ 
tion Transmission at Various Friction 
Wheel Positions. 























































Constructional Features of Cyclecars 


483 


is meshed with a bevel gear on a cross shaft. The gearing is encased. 
At either side of the case a sprocket is mounted that is adapted to turn 
freely on the cross shaft unless it is clutched to it by a sliding jaw 
clutch. One of the sprockets connects with a large sprocket on the 
rear hub, the other is joined to another sprocket of smaller diameter 
than the neighboring one. When the dog clutch is moved over as 
indicated in the illustration, the high-gear sprocket is clutched to the 
cross shaft, while the low-gear sprocket is free to revolve idly on that 
member. The clutches are attached to a common shifting rod that 



Fig. 308.—Positive Clutch Controlled Two Chain Change Speed 

Gearing of Morgan Cyclecar. 


permits of three positions. One of these gives the high speed, an inter¬ 
mediate point is a neutral position in which neither sprocket is driven 
by the cross shaft, while the third is the low-speed position. Lt will 
be evident that only one sprocket will drive at a time. It is necessary 
to provide a master clutch ol the friction type with this form of trans¬ 
mission because the speed-changing clutches will be much too harsh 
in action, and would take hold much too suddenly to be used alone. 

The planetary form of gear which has been used to some extent 
in both motorcycles and automobiles has also been adapted to cycle- 






































































484 


Motorcycles , Side Cars and Cyclecars 


car use. Its action is very similar to that of the simpler forms used 
in motorcycles previously described.. There is one difference, however, 
and that is the cyclecar transmission of this type is provided with a 
reverse ratio" in addition to the slow speed provided on motorcycles. 
The construction of a planetary gearset intended for shaft drive is 
shown at Fig. 309, while the method of construction followed when 
the transmission is attached to the cross shaft is clearly outlined at 
Fig. 310. In this case, the drive is by roller chain from the engine 
to a sprocket, to drive the transmission or change-speed gearing. 



Fig. 309.—Part Sectional View of Two Speed and Reverse Planetary 
Gearing for Cyclecars and Light Cars. 


This assembly is mounted on a hollow shaft or quill through which the 
cross shaft passes. The ends of the cross shaft are tapered to receive 
the usual V-belt pulleys or a roller chain sprocket at each end for the 
final drive to the rear wheels. 

Power Transmission Methods. —The usual method of driving 

the true cyclecar is by the V-belts that have been previously described 
at length because used in motorcycle design. The V-belt may be used 
in two forms: the belt may be very long and extend practically the 
length of the cyclecar or it may be considerably shorter as is the case 






























































































































Constructional Features of Cyclecars 485 



Fig. 310.—The Spacke Two Speed and Reverse Planetary Gearset 
Applied to Countershaft for Final Drive by V Belts. 


in motorcycles. On the original simple cyclecar forms, the long belts 
were utilized because they permitted a certain degree of free engine 
action if the rear axle was moved forward so that belts were slackened. 
When it was desired to drive the vehicle, the entire axle is moved 
back until the belt tension is sufficient to grip the pulleys positively. 
This method of control, which is shown at Fig. 311, is not used very 
widely because it was found that the belts did not respond very kindly 



Fig. 311.—Diagram Showing Method of Obtaining Clutching Action 

With V Belt by Moving Rear Axle. 































Motorcycles , Side Cars and Cyclecars 


480 



Fig. 312.—Diagram Showing Method of Using De Luxe Motor and 
Spacke Cyclecar Transmission With Final Drive by V Belts. 


to the friction present between the small driving pulley and the belt 
whenever it was desired to obtain a free engine action. The approved 
method of transmission when a planetary transmission is used is 
shown at Fig. 312. In this, a Spacke two-cylinder motor is arranged 
in much the same manner as it is placed in a motorcycle, i. e., one 
cylinder is behind the other. The drive from the sprocket attached 
to the engine crankshaft is to the similar member secured to the 
planetary transmission such as shown at Fig. 310. The drive from 
the V-pulleys at the end of the cross shaft is to the larger members 
attached to the rear wheels, which in this case are not shown in the 
illustration. The movable rear axle used on the early forms of cycle- 
cars had important advantages in that the vehicles provided with 
this method of transmission are the simplest types that can be de¬ 
vised. 










































Constructional Features of Cyclecars 


487 


It will be observed that the chassis construction outlined at Fig. 
313 is a four-wheel motor vehicle reduced to its elementary form. 
The engine, which is an air-cooled motorcycle type having two 
cylinders set at an angle, is secured at the front end, where it will 
get ample cooling. The wire wheels are carried by miniature steering 
knuckles attached to a light tubular front axle. The spring suspen¬ 
sion at the front end is by semi-elliptic leaf springs which combine 
the duties of a resilient support for the frame as well as distance or 



radius rods for the axle. The wood frame is extended to the rear, 
and in most cyclecars it is made of ash. The drive from the sprocket 
on the engine crankshaft is by a motorcycle roller chain to a larger 
sprocket on the countershaft. At each side of the countershaft V-belt 
pulleys are mounted which drive the rear wheels through leather belts. 
In the simple form shown the clutching action is obtained by sliding 
the axle back to tighten the driving belt and produce forward motion, 














488 


Motorcycles , Side Cars and Cyclecars 




Fig. 315.—Front and Rear Axle Construction for Simple Type 

Cyclecar. 


while it is pushed forward to loosen the belt and obtain a free engine 
action by the belt slipping over the pulleys. 

In the cyclecars that follow automobile practice, one finds the same 
method of drive used as generally employed in the larger vehicles. 












































































































Constructional Features of Cyclecars 489 

An example of the unit power plant and shaft drive of the Humberette 
(English) is shown at Fig. 314. The motor, which is a twin-cylinder 
air-cooled form, is made in a unit with the clutch and change-speed 
gearing. From the rear end of the change-speed gear, a propeller 
shaft extends, that is provided with a universal joint at each end that 
drives bevel gearing in the rear axle. Complete description of all 
these methods of drive will be found in the writer’s work on auto¬ 
mobiles previously mentioned. 

The method of attaching the V-belt pulley to a motorcycle or cycle- 
car wheel is clearly outlined at Fig. 315. The wheel which is of the 
usual wire spoke form with the exception of employing heavier rim 
section, hubs and spokes than are generally used on bicycles, but of 
about the same strength as provided for motorcycles, revolves on a 
stationary spindle attached to a tube that forms the rear axle. The 
V-belt pulley, which is a steel member rolled to the proper shape, is 
attached to the rim by a series of arms riveted to the pulley and to 
the rim member. 

Steering Arrangements. —-There is some diversity of practice in 
the steering arrangements used on cyclecars. The first form evolved 
had the entire front axle movable around a fixed central point, though 
the later designs for the most part use a pivoted steering knuckle 
construction that is so generally applied in automobile construction. 
Two forms of steering gears are outlined at Fig. 316. That at A 
shows a rack and pinion reduction construction in which the rotary 
motion of a small pinion at the end of a steering post is transformed 
to a lateral movement of the rack with which it meshes. A drag link 
connected to this rack transmits its motion to the tie-bar connecting 
the two steering knuckles and the wheels may be set at the proper 
angle for steering with minimum effort. This is not true of the form 
where the entire front axle swings, because it is more difficult to move 
the wheels in soft sand or when the wheels are in ruts when the entire 
axle is moved than when the wheels are carried on spindles and the 
axle is fixed. 

In order to simplify the construction, some designers have used 
cables passing around a drum at the end of a steering column to join 
the steering knuckle arms. The use of the drum provides a reduction 
in effort when steering the vehicle on account of the leverage obtained 


490 


Motorcycles , Side Cars and Cyclecars 


when the cables are wound close to the center of the steering column. 
With this system, it is essential that tension springs be provided to 
keep the cables taut at all times. When the entire front axle is swung 
around the cable construction is generally followed, though when the 
wheels are mounted on movable steering spindles secured to a fixed 
axle the Ackermann or direct rod system is considered much more 
positive and satisfactory. The cables will wear in time, especially 



Fig. 316.—Methods of Steering Cyclecars. A—By Rack and Pinion 
Reduction Gear. B—By Wire Cables and Drum. 


if they rub against any part of the frame structure. When rods are 
used these can be proportioned to take the strain and there is no 
depreciation of the steering system that is apt to result in derange¬ 
ment of this important directive function. 

Methods of Springing. —Careful attention must be paid to proper 
springing of a light vehicle, such as a cyclecar, and it is imperative 
that the supporting members and their arrangement should be care- 






























Constructional Features of Cyclecars 491 

fully selected in order that they may be resilient and yet strong. 
While the supporting systems followed in automobile practice have 
been adhered to very closely by cyclecar designers a number of dis¬ 
tinctive forms in which the springs perform the dual function of axle 
and springs have been evolved. The simpler types of springs are the 
most common, namely, the semi-elliptic and the quarter elliptic forms, 
though several instances where full elliptic springs are used may be 
noted. The distinctive spring suspension of the Falcon cyclecar is 
shown at Fig. 317. In this, the frame is supported by three points, 



Fig. 317.—Diagram Showing Flexibility of the Falcon Cyclecar 
Chassis and Three Point Support System. 


one at the front and two at the rear. The front-spring construction 
is such that these members replace the usual form of axle, inasmuch 
as they are attached directly to members on which the wheels are 
mounted. The springs are supported by a block at their center point 
which is pivoted to a steering head that permits the axle to be swung 
around for steering. The supporting pivot provides a very effective 
three-point support because one wheel may be considerably higher 
than the other without displacing the frame. This method of com- 
































492 


Motorcycles , Side Cars and Cyclecars 



Fig. 318.—Defining Control Methods of Typical Foreign Cyclecars. 





























Constructional Features of Cycle cars 


493 


bining the spring and axle functions is also followed on the Imp 
cyclecar, though modified to some extent. 

Cyclecar Control Methods. —Cyclecar control methods differ 
widely, and depend entirely on the system of power transmission 
employed. For example, the control group shown at Fig. 318, A, is 
adapted to vehicles of the Bedelia type. The engine speed is varied 
by the usual spark and throttle-control levers which in this case are 
secured to the side of the frame. A pedal is provided for raising the 
exhaust valves and applying the foot brake. A long side lever is 
utilized to move the axle back and forth to obtain either, the free 
engine or clutch action and to apply the brakes. When the axle is 
moved back, the belt tension is increased and the engine drives the 
wheels. When the axle is moved forward, a free engine action is 
obtained up to a certain point beyond which a continued movement 
of the side lever will apply brakes to the V-groove pulleys on the rear 
wheel. 

If this method is contrasted with the complete control system, 
shown at B, it will be evident that in the latter the general arrange¬ 
ment is much the same as prevails in automobile practice. The 
engine speeds are controlled by the usual spark and throttle levers 
which are mounted on the steering column. Three pedals are pro¬ 
vided: one to control the clutch, one to govern the throttle of the 
carburetor, and the third to apply a foot brake. The lever inside of 
the body is used in changing speeds while that on the outside applies 
the emergency brake. The control system of the Auto Carrier three- 
wheel cyclecar, previously described, is shown at C. Steering in this 
case is by a steering bar instead of the usual hand wheel. The spark 
and throttle levers are conveniently mounted at the side of the body, 
and regulate the magneto contact breaker and the throttle slide 
through Bowden wire mechanism. Owing to the peculiar form of 
transmission employed, one handle is used for the high speed and 
a pedal is provided for the low speed. The other pedal applies the 
brake. Another form following current automobile practice very 
closely is shown at D. This is practically the same in general arrange- * 
ment as the form shown at B, except that two additional controls 
are provided. One of these is an exhaust valve lifter, the other is a 
foot-operated plunger arrangement intended to work the oil pump. 




494 


Motorcycles , Side Cars and Cyclecars 


The methods of starting the engine and controlling its speed that 
are given in the following chapter will apply just as well to the pow r er 
plants used in cyclecars as to those designed for motorcycle pro¬ 
pulsion. The general hints for maintenance and repair of power 
plant and transmission systems, also location of troubles and lubri¬ 
cation advice can be applied to advantage by the cyclecarist, as well 
as the motorcyclist. A careful study of the chapters on power plant 
operation, carburetion and ignition will prove just as valuable to the 
person interested in cyclecars only as to the motorcyclist because 
the principles that obtain and on which the action of the various 
parts of the power plant group are based apply to all forms of gasoline 
engines regardless of where used. 


CHAPTER VIII. 


MOTORCYCLE MAINTENANCE, OPERATION AND REPAIR 

Motorcycle Equipment—Lighting Systems—Alarms, Tools and Supplies— 
Directions for Starting Motor—Instructions for Operating Motorcycle— 
Advice on Lubrication—Motorcycle Troubles—Classification of Engine 
Defects—Testing Ignition Sj^stems—Common Faults in Carburetion 
Systems—Causes of Lost Compression—Causes of Irregular Motor 
Operation—Conditions Producing Overheating—Causes of Noisy 
Operation—Valve Removal and Grinding—Removing Carbon Deposits 
—Instructions for Running De Luxe Motors—Defects in Power Trans¬ 
mission Elements—Testing for Chain Alinement—How to Adjust Chains 
—Slipping Belt Drive—Care of Leather Belts—Care of Wheels— 
Common Defects in Clutches—Derangements in Change Speed Gearing 
—Adjustment of Brakes—Repairing Inner Tube Punctures—Outer 
Casing Repairs—Advice to Purchasers of Second Hand Motorcycles. 

Motorcycle Equipment. —Of the innumerable accessories that 
have been devised for use of the motorcyclist, either for his personal 
benefit or to be used in connection with the machine, fully three- 
quarters are unnecessary, and can be easily dispensed with. It is 
not the writer’s purpose to describe all of the various articles of equip¬ 
ment because the opinions of the various riders differ as to what 
should be considered necessary and what may be just as well omitted. 
Assuming that the rider has received a bare motorcycle without any 
auxiliary fittings whatever, it will be well to enumerate briefly some 
of the accessories that are really necessary in order to insure safety 
and comply with the law. 

The first thing needed is adequate lighting equipment, and in most 
states a tail light is required as well as a head light. The next fitting 
prescribed by law is some form of signal or alarm by which the motor¬ 
cyclist may notify other users of the highway of his approach. There 
is always a certain number of tools and spare parts that can be 

495 



Motorcycles . Side Cars and Cycle cars 


49 (> 


carried to advantage and that are not furnished with the machine. 
The equipment of a motorcycle does not include a speedometer unless 
one purchases a special model that is sufficiently expensive to have the 
cost of the accessories included in the purchase price. 

The speedometer, which indicates the speed attained, and which 
also includes a mileage recorder, is a very necessary fitting. One 
is not only able to keep the speed in accordance with the legal require¬ 
ments, but a reliable speed indicating device forms a good check on 



Fig. 319.—Forms of Gas Lamps and Generators Used in Motorcycle 

Lighting Systems. 


motor action and when to oil. The mileage recorder enables the 
rider to keep track of the service given by tires or other parts, and 
the amount of gasoline and oil consumed in covering a given mileage. 
The cost of the average motorcycle speedometer will be exceeded by 
a substantial margin if fines are paid for just one violation of the 
speed law, so it is much better to insure against arrest and obtain all 
the other advantages by investing in a speedometer than it is to pay 
more than the cost of one of the devices to swell the bank account of 
some rural constable. Another article of equipment is a watch and 





























Motorcycle Maintenance , Operation and Repair 497 


holder designed for attachment to the handle bars. Weed chains 
should be provided for the tires to minimize skidding; they are light 
and easily carried as they occupy but little space when not in use. 

Lighting Systems. —The kerosene burning lamps used on the 
bicycle do not provide sufficient illumination for the motorcycle, on 
account of the greater speed of the power-propelled form. The 
various forms of lamps that are widely employed utilize acetylene 
gas as fuel and throw a brilliant light which will illuminate the road 
for several hundred feet ahead ol the motorcycle. The lamp shown 



Fig. 320.—Diagram Showing Construction of Gas Lamp and Acetylene 

Generator. 


at Fig. 319, A, is combined with the gas generator, which is a simple 
device for producing acetylene gas by the chemical action of water 
on calcium carbide. While the generator has been widely used, it 
is being superseded in many cases by the Prestolite tank in which the 
gas is stored under pressure, and from which it may be taken as needed 
by a simple operation of the tank valve. The searchlight shown at 
B is a separate type which can be used in connection with either the 
separate generator shown at C or the gas tank with which all are 
familiar. A small gas burning lamp designed for attachment to the 
rear mud guard is shown at D. 




















































498 


Motorcycles , Side Cars and Cyclecars 


The method of operation of a generator may be clearly understood 
by referring to Fig. 320. As will be apparent, the device consists of 
two parts, an upper chamber to hold water and a lower portion 
divided in two compartments, one of which holds carbide while the 
other provides space for the gas to collect in. The carbide in the lower 
chamber surrounds a central tube in which measured quantities of 
water from the upper chamber are allowed to drip. The water is 
controlled by a needle valve, and the more water admitted the more 
energetic the liberation of gas becomes. The gas passes through a 
cooling chamber at the bottom of the upper portion that holds the 
water, and from there it passes to the burner in the lamp, through a 
length of rubber hose. After the carbide has been used up, which 
is evidenced when it has turned from the state of crystals or lumps 
to dust, the lower portion of the generator must be removed and 
thoroughly cleared out and fresh carbide inserted before one will 
obtain any more gas. 

The combined electric starting and lighting system of the Indian 
motorcycle has been previously described at length, but other sys¬ 
tems of electric lighting have been offered that are adapted to be fitted 
to motorcycles of any pattern. The simplest method of obtaining 
electric lights is to use a battery of some form carried by a simple 
container, which in some cases may be attached to the lamp. Either 
dry cells or storage batteries may be used. If much night riding is 
to be done, the storage battery will be the most practical form, 
though dry-cell arrangements will give very good light if properly 
installed. 

As previously pointed out, any chemical current producer becomes 
depleted as it is used, so a number of small generators have been 
evolved to furnish the current for lighting. One of these, shown at 
Fig. 321, is driven by a friction wheel that bears against the front 
tire, and charges a storage battery which, in turn, delivers current 
to the searchlight. The object of using storage battery, in connection 
with mechanical generator, is to insure the delivery of a uniform 
current to the lamp filament. As the electricity generated by the 
simple form of dynamo or magneto will vary in quantity as the 
speed the armature turns varies, when the motorcycle is driven fast, 
excess current might be generated that would burn out the lamp 


Motorcycle Maintenance , Operation and Repair 499 

filament. When running slow, the current is weak and the illumina¬ 
tion proportionately feeble. If instead of delivering current directly 
to the lamp, the dynamo delivered its energy to a storage battery, 
that member serves as a reservoir and an equalizer, and delivers 
current of constant value to the lamp. Some attachments are offered 
wherein the dynamo is driven from the motor by small wire spring 
belts or round leather forms. These have a defect, in that it is 
difficult to obtain reliable service from the belts which are constantly 
breaking. The drive from the tire is not perfect by any means, as 



the friction drive pulley of the magneto will produce a certain amount 
of depreciation at the point of contact on the tire, and may slip when 
the tire becomes coated with water or mud. If a mechanical generator 
of electricity is to be included in the motor cycle equipment this 
should be preferably built in as a part of the machine, and be driven 
by positive gearing, as is the case on the Indian motorcycle. 

Alarms, Tools and Supplies. —On machines that are provided 
with electric lighting, it is not difficult to use electric alarms in the 
form of vibrating diaphragm horns which are set in action by a simple 
pressure on a push button. When a machine is not provided with 
batteves and a loud alarm is desired, a mechanical horn such as shown 



















































500 


Motorcycles , Side Cars and Cyclecars 


at Fig. 322, A, will produce a louder tone than the usual electric 
buzzer arrangement. This is a diaphragm form, and is similar to the 
type that is so widely used on automobiles. A downward pressure on 
the plunger extending from the back of the horn casing sets the train 
of gears in motion which, in turn, actuate the diaphragm at a rapid 
rate. The simpler forms of bulb operated horns such as shown at 
B and C are also adapted for the motorcycle, but these do not provide 



Fig. 322.—Popular Forms of Motorcycle Alarm Signals. 

the best alarm when touring, inasmuch as their note does not have 
a very great carrying power. The shriek of the mechanical horn can 
be heard for many hundred feet. 

It is difficult to outline the tools that should be provided because 
so much depends upon the character of the machine and its equip¬ 
ment. Most motorcycle manufacturers provide the special tor Is that 
































































Motorcycle Maintenance , Operation and Repair 501 

are needed to get at any adjustments or nuts and bolts that would 
not be accessible with the ordinary tools obtained in the open market, 
so it will not be necessary to describe the special socket wrenches or 
spanners that fit only certain makes of machines. The main item of 
the average tool kit is a monkey wrench of special, light, thin form 
that still has a large enough opening to take the largest nut on the 
machine. For instance, if the inlet-valve cage screws into the cylinder, 
or if valve chamber caps are used the wrench should be large enough 
to move either of those members, which are usually the largest of the 
parts that must be handled by the wrench. A small size wrench of 
the bicycle type is also convenient and does not occupy much space. 
Two screw drivers should be provided, one small one with a blade 
that will permit removal of the smallest screws on the machine (such 
as those on the magneto) and one a little larger in size, preferably 
short and stubby with a strong blade for handling the other members 
that are screwed in tighter, and which could not be very well removed 
with a light screw driver. 

A pair of combination pliers are usually part of the equipment, but 
if these are not provided by the maker the rider should see that they 
are included in the tool outfit. The best all around form for motor¬ 
cycle use is that which is provided with a joint of such form that the 
opening between the jaws may be varied. The jaws are provided 
with a flat portion at the extreme end and below this part, which is 
used for gripping flat stock, a semi-circular, serrated opening is pro¬ 
vided in each jaw for gripping pipe or round objects. The lower 
portion of the jaws near the hinge are usually sharpened to a cutting 
edge and move over each other with a shearing action. This portion 
serves as a wire cutter. One or two small files are also desirable, as 
many occasions arise where they will prove useful. Other tools should 
be provided depending upon the transmission employed. If the V-belt 
is used, a belt punch or awl as well as several spare connectors may be 
included. If drive is by chain a chain tool for removing the rivet 
from the links, and a number of spare connecting links are necessary. 

Among the spare parts that may be carried to advantage may be 
mentioned a small spool of copper wire about No. 16 gauge, a length 
of high tension cable, and a number of assorted bolts, split pins, nuts 
and washers that conform to those used on the machines. If a single 


502 


Motorcycles , Side Cars and Cyclecars 


cylinder engine is employed as a power plant two spare spark plugs 
should be carried, while if it is a twin cylinder, three extra spark 
plugs should be included. To insure against breakdowns when away 
from the source of supplies, a few spare magneto parts such as the 
high tension carbon brush holder, a platinum pointed contact screw 
and a contact breaker bell crank will be found of advantage. 

A roll of tire or insulating tape, and a complete tire repair outfit 
should figure m the equipment. The average outfit for inner tube 
restoration consists of a piece of emery cloth, a tube of cement, and 
some patches of assorted sizes. Patches may be obtained that do 
not require any cement as it is already incorporated with them, and 
a couple of these may be provided for an emergency where the regular 
cement would not work properly. Small tire irons to remove the 
casing from the rim and an air pump, as well as a number of spare 
valve insides, complete the outfit for repairing the inner tube. In 
case of a blow out, or a serious cut in the outer casing, it will be well 
to have an inside blow out patch and a tire gaiter handy. The inside 
patch is a piece of heavy canvas, 5 or 6 inches long and wide enough 
to conform to the curved interior portion of the tire completely when 
doubled over. The outer sleeve is made of leather or rubber and 
fabric, and is provided with a lacing by which it may be tightly drawn 
in place around the injured portion of the casing. If going on a tour 
of any magnitude, a complete inlet and exhaust valve assembly and 
several extra inner tubes will complete the kit. 

The problem of carrying tools and supplies is not an easy one to 
solve on a motorcycle, though many very practical bags and carrying 
cases have been designed that will fit the top of the luggage carrier, 
or that are adapted to be carried one on either side of that member. 
These provide room for considerable material and enough equipment 
for a trip of some magnitude may be easily stowed away. The bag 
shown at A, Fig. 323, is intended for attachment to the side of the 
luggage carrier, and not only provides a large amount of storage space 
inside but has a smaller tool bag attached as well as a pocket to carry 
the oil can. The form at B is intended to be carried on top of the 
luggage carrier and is considerably larger than that designed for 
attachment to the side. The bag shown at C is also intended for the 
top of the luggage carrier, and when flanked on either side with a bag 


Motorcycle Maintenance , Operation and Repair 503 

of the form shown at A much storage space is available. Where 
machines are driven by belt, if one undertakes a long tour and the 
belt has seen considerable service, it may be well to carry a spare 
member in a special casing such as shown at D. The interior of this 
case is divided into two concentric compartments, the outer one serv¬ 
ing for the belt, the inner one to carry the spare inner tube. If a 
side car is fitted, an opportunity for carrying considerable luggage 



Fig. 323.—Examples of Cases Adapted for Carrying Tools or Supplies 

on Motorcycles. 


may be taken advantage of by fitting a luggage carrier or rack, as 
shown at Fig. 324, to the back of the side car body. 

I Directions for Starting Motor. —Assuming that the rider has just 
received a machine, and that it has come crated, and also that he is 
not familiar with motorcycle operation, we may give the following 
general instructions: After the machine has been uncrated, and the 
handle bars, saddle and pedals attached in their proper places, the 



























504 


Motorcycles , Side Cars and Cyclecars 


first step is to see that the tanks are filled with gasoline and oil. As 
a rule, the filler caps are very plainly marked to indicate the purpose 
of the container to which they are fitted. In filling the tank with 
fuel, filter the gasoline by passing through a chamois skin which in¬ 
sures positive removal of all dirt and water. Be sure to fill the oil 
tank with the proper grade of lubricant, which must be a good air¬ 
cooled engine cylinder oil, and preferably of the brand recommended 
by the maker of the machine. Before attempting to start the motor, 
become familiar with the various parts of the controlling apparatus. 
In most American machines the gas supply is regulated by one of 
the movable grips on the handle bar, and which one it is can be easily 

ascertained by moving 
both of them in turn and 
seeing which operates on 
the throttle lever at the 
top of the carburetor. In 
some machines, the grip 
is turned in one direction 
to close the throttle 
which would be just the 
same as that to open the 
throttle in other motor¬ 
cycles. The proper mode 
of procedure can only be 



Fig. 324.—Application of Luggage Carrier at 
Rear of Side Car Body. 


determined by experiment. The grip on the other handle bar is used 
for advancing the timer or contact breaker of the magneto when 
turned in one direction and for raising the exhaust valves if 
turned to the other extreme position. In some motorcycles, the 
exhaust valves are raised by a special lever carried by the handle 
bars. The clutch of most motorcycles is operated by a hand lever 
at the side of the tank, and in some machines a smaller lever will 
be mounted at the side of the tank that is connected directly 
with the contact breaker of the magneto. When a two-speed gear of 
the planetary type is used, a single-control lever usually serves to 
control both high and low speeds, and this member corresponds to 
the usual free engine clutch actuator. When an individual or shifting 
clutch, two-speed gear is used, the master or friction clutch is often 


















Motorcycle Maintenance , Operation and Repair 505 

shifted by a foot lever, while the speed changing is effected by a very 
small lever carried on the upper frame tube. 

The first thing to do is to learn to control the motor. To do this, 
raise the rear wheel of the machine from the floor by the stand pro¬ 
vided for that purpose, open the valves in the gasoline line so the fuel 
will flow to the carburetor and supply a couple of pumpfuls of oil 
to the engine base. If a sight feed device is provided, this should 
be set to feed about eight drops per minute. Prime the carburetor 
by pressing the priming pin and holding that member down until 
gasoline flows from the bottom of the device. This shows that the 
spray nozzle has overflowed which indicates that it is clear of dirt. 
Set the spark about half way advanced, open the throttle slightly, 
and raise the exhaust valves by whatever means are provided for 
that purpose. Pedal briskly and turn the motor over at a fair rate of 
speed, and then drop the exhaust valves and the motor should start. 
After the motor has been started, become familiar with the action 
of the spark and throttle levers or control grips by moving them back 
and forth, and noting the effect of the various positions on the be¬ 
havior of the engine. Do not run the engine unnecessarily fast when 
on the stand. 

Instructions for Operating Motorcycle. —After having learned 
to manipulate the motor and control its speed on the stand, the motor 
may be started and allowed to run slowly, and the high-speed or 
free-engine clutch lever may be set in the free engine position. This 
may be clearly noted by pressing on the brake pedal with the engine 
in motion. If the rear wheel stops rotating without affecting the 
engine speed, it indicates that the clutch is free and functioning 
properly. If applying the brakes stops the motor as well as the rear 
wheel, it shows that the clutch is not properly released, which may 
mean that the lever is not in the proper position or that there is some 
defective condition in the clutch itself. The machine is then dropped 
off of the stand with the clutch lever in the off position, and, after 
the rider has mounted, the engine may be speeded up and the clutch 
lever moved gradually until the motorcycle acquires a certain momen¬ 
tum, after which the clutch may be engaged positively. 

If the machine is a two-speed form, the start may be made on the 
high speed without any trouble, as the friction clutch will provide 


506 


Motorcycles , Side Cars and Cyclecars 


gradual application of power if it is controlled properly. When start¬ 
ing on a hill or in sand, it will be well to start on the low gear and 
throw into the high only when the top of the hill is reached, or road 
conditions become more favorable. Do not slip a clutch of any type 
unnecessarily, because this will produce wear of the friction surfaces. 
In operating two-speed gears of the shifting clutch type or of the 
sliding gear pattern, always be sure that the master clutch is com¬ 
pletely released before endeavoring to shift gears. When shifting 
from high speed to lower speed, always slow down the engine or wait 
until the speed of the motorcycle drops to the point that will corres¬ 
pond to the gear ratio obtained by the reduction gearing. In changing 
from the low to the high gear, accelerate the engine slightly to speed 
up the machine before the shift is made. Complete instructions for 
operating the engine, and proper manipulation of spark and throttle 
levers, as well as starting by hand crank or foot starter, are appended. 

If one attempts to set an engine in motion by means of a hand crank 
with the spark lever advanced so an early spark is obtained, the motor 
may “kick back,” and this reversal of motion, which is due to prema¬ 
ture combustion, may sprain the wrist. It will be well to open the 
throttle or gas lever a little to insure that a charge of combustible gas 
will be inspired into the motor. The engine should be turned over 
several times as briskly as possible with the spark lever in full retard 
position and exhaust valves raised. The timer or contact breaker is 
then advanced slightly and the exhaust valves allowed to seat them¬ 
selves. The hand crank is pushed in until it engages the ratchet 
member connected to the crankshaft, and then the motor should be 
turned by pulling up on the starting handle with the left hand. 

The hand crank should always be engaged so that an upward pull 
will be necessary to turn the crankshaft, and a point that cannot be 
too firmly impressed upon the embryo motorcyclist’s mind is that 
gasoline engines should always be started by pulling up on the handle 
of the starting crank, never by pushing down. If the starting handle 
has been properly placed and the engine has been turned over enough 
without the spark so the cylinders hold a gas charge, and the timer 
is advanced when a decided resistance is felt as the crank is turned 
indicating that the piston in the cylinder in which the gas charge is 
about to explode is nearing the compression point, a single, quick, 


Motorcycle Maintenance , Operation and Repair 507 

strong pull on the crank should be sufficient to start any properly 
adjusted motor. 

All motorcycle motors have a certain degree of flexibility, i. e., they 
may be run slow or fast, and the speed may be accelerated or cut down 
as desired within a range from 200 revolutions per minute to the 
maximum, 2,500 or 3,000, which will vary with the type of motor. 
This is an important advantage, inasmuch as it permits one to regulate 
the cycle speed on most occasions by a touch of the throttle grip alone. 
The engine speed of practically all motorcycles is controlled by two 
ways, though usually these are employed in conjunction. One of 
these consists of varying the time of the spark in the cylinder, the 
other regulating the amount of gas supplied. The spark and throttle 
levers, while designed to be manipulated independent of each other, 
usually move with a certain definite relation. It would not be good 
practice to run an engine with the spark lever way advanced and gas 
supply throttle nearly closed; nor would good results be obtained if 
the spark lever was retarded and the throttle opened, as it is desired 
to increase the motor speed. It is not difficult to understand the 
function of the throttle lever and how the admission of more gas to 
the cylinders would act in creating more power, just as augmenting 
the steam supply to a steam engine will increase its capacity. 

The rules for manipulation of the spark lever are not so well under¬ 
stood. In order to make clear the reason for intelligent manipulation 
of the spark handle, there are certain points that must be considered. 
On most motorcycles, there is a position of the spark lever at some 
point of the arc over which it moves which corresponds to the normal 
firing point. If the spark lever is not advanced beyond this position, 
and the motor is turning over slowly, the gas in the cylinders is being 
exploded when the pistons reach the end of their compression stroke. 
When the gas is fully compacted, the explosion or power obtained 
from combustion is more powerful than of the spark fired gas which 
was not compressed properly. The electric spark is not produced at 
the exact time that the motor should be fired at all speeds, and if 
the spark was supplied the very instant of full compression, irrespective 
of the speed of rotation, there would be no need of moving the spark 
lever. 

Not only is the current apt to lag, but it takes a certain definite 




508 Motorcycles , Side Cars and Cyclecars 

amount of time to set fire to the gas. It requires the same amount of 
time to ignite the gas, of given composition, regardless of the speed of 
the motor. If the motor is only turning at a few hundred revolutions 
per minute, there is ample time to ignite all gas charges positively, 
but if the motor speed increases and the explosions occur oftener, then 
one must compensate for the more rapidly occurring combustion 
periods by arranging to start igniting the gas earlier so the explosion 
will occur when the piston is at its highest point in the cylinder. The 
compensation for lag is made by advancing the spark. The spark 
lever on the handle bar or tank moves a commutator, if battery sys¬ 
tem is employed, or the magneto contact breaker box, if that form of 
current producer furnishes the ignition energy. The amount of spark 
advance needed depends on engine speed and the greater the piston 
velocity the more the spark should be advanced. 

It is possible to advance the spark lever too far, and, when this 
occurs, the gas is exploded before the piston reaches the top of its 
stroke, and premature explosion takes place. As a result of this, the 
upwardly moving piston is forced to overcome the resistance exerted 
by the expanding gas of the ignited charge in completing the remainder 
of the compression stroke, and before it will return on the power 
stroke. The inj urious back pressure on the piston reduces the capacity 
of the motor and a pounding noise similar to that produced .by loose 
motor parts gives positive indication of premature ignition due to 
excessive spark advance. 

At the other hand, if the spark lever is not set as far forward as it 
should be, the explosion may be late because of the ‘’retarded spark.’’ 
If the spark occurs late in the cycle, the charge is not fired until the 
piston has reached its highest point and after it has completed a small 
portion of its downward movement. As the point of maximum com¬ 
pression is passed and the piston moves down in the cylinder, the size 
of the combustion chamber augments and the gas begins to expand 
again before it ignites. Owing to the moderate compression, the 
power resulting from explosions is less than would be the case with a 
higher degree of compression. To secure power, it is necessary to 
supply more gas to the cylinders. Driving with a retarded spark 
produces heating of the motor and is wasteful of fuel. 

For ordinary running, the spark lever is usually placed about mid- 


Motorcycle Maintenance , Operation and Repair 509 

way of its travel on the sector, and as a general rule an engine with 
magneto ignition does not require the frequent manipulation of the 
spark necessary when current is produced by chemical means. As 
the engine speed increases, the current produced by the magneto is 
proportionately augmented, and the spark lever need not be advanced 
from the center position except under conditions which permit of 
exceedingly high engine speeds. 

Summing up, it will be patent that the greatest economy of fuel 
will result when the motorcycle is operated with as little throttle open¬ 
ing as possible, and with the greatest spark advance the motor speed 
will allow. To obtain maximum power, as in hill climbing on the 
direct drive, the spark lever should never be advanced beyond center 
and the throttle should be opened as wide as possible. For extreme 
high speed, the spark is advanced as much as possible and the throttle 
opened wide. 

Advice on Lubrication. —One of the most important considera¬ 
tions, making for efficient action and promoting long life of the 
mechanism, is to provide proper lubrication. The lubrication of the 
power plant is the most serious proposition. The best oil is the only 
kind that should be used, as more good motors have been ruined by 
the use of lubricant of improper quality or insufficient quantity than 
have been destroyed by accidents. If a drip feed is used, a medium 
grade oil may be employed in warm weather, but a light grade will be 
necessary in cold weather. If the supply is by mechanically operated 
pump, a heavier bodied lubricant may be used than when the drip 
feed system is employed. When oil is introduced to the engine crank¬ 
case by means of a hand-operated pump which means that lubrica¬ 
tion is directly under the control of the rider, one pump full of oil, 
every 8 or 10 miles, at speeds of 20 miles per hour will be sufficient. 
For a speed of 30 miles per hour, it will be necessary to inject a pump¬ 
ful every 5 or 6 miles. It is better to over-lubricate a machine than 
not to supply enough, so any time that the rider is in doubt it will be 
well to inject another pumpful on general principles. If the engine is 
over-lubricated, the exhaust will be smoky. If a mechanically 
operated oil pump is used and the hand pump is provided only as 
an auxiliary, it will not be necessary to supply oil except at such 
times that the engine is run exceptionally fast. 


510 


Motorcycles , Side Cars and ("y cl rears 



Fig. 325. —Diagram Showing Location of Control Levers on Royal 

Enfield Motorcycle. 

Among some of the points that should receive oil every time the 
machine is used may be mentioned the valve lifters, or rocker arms, 
the free engine clutch, the steering head, and the various hinges and 
joints on the spring frame or spring fork. If a two-speed gear is pro¬ 
vided the supply of lubricant should be renewed every 300 miles. 
Planetary gearing requires more lubricant and a lighter semi-fluid 
grease than either the sliding clutch or sliding gear forms. It is well 
to put a few drops of oil in the front hub and coaster brake oilers every 
day. About the only point on the motorcycle that can receive too 

































Motorcycle Maintenance, Operation and Repair 511 

much oil beside the engine interior is the magneto, and only a few 
drops are required every two or three months to insure adequate 
functioning of this device. A special light oil is necessary for the 
magneto, and a good grade of sewing machine or 3 in 1 oil will be 
found satisfactory for this purpose. The hand oil-can may be filled 
with cylinder oil which can be used on all points of the machine, 
because if it is good enough for the engine interior, it is much better 
than needed for the various external parts. The ball bearings in the 
hubs, countershaft, and steering head may be packed with grease 
once or twice a season which will be adequate. 



Fig. 326.—Diagram Showing Lubrication Points on the Royal Enfield 

Motorcycle. 






A diagram at Fig. 326 shows the points on the Royal-Enfield motor¬ 
cycle which demand lubrication. About the only point that needs 
to be explained is the drip feed system which is set to pass 30 or 40 
drops per minute. When it is understood that this device is inter¬ 
posed in a lubricating system of the constant flow form in which 
circulation is maintained and the oil used over and over again it will 
be apparent that it would not make any difference if the lubricant 
passed through the sight feed glass in a steady stream. With the 
sight feed lubricators ordinarily provided on American machines, 
if these are set to feed faster than 10 or 12 drops per minute, the 






































512 Motorcycles , Side Cars and Cyclecars 

engine base will receive too much oil, because there is no return pipe 
to direct the surplus lubricant back to the oil tank. 

Motorcycle Troubles. —When the motorcycle was first evolved, 
it was a composite structure of two distinct assemblies, neither of 
which was adapted to the other. The gasoline motor could not be 
placed in the ordinary bicycle frame to advantage, and therefore gave 
continued trouble. As light bicycle frame construction was not 
sufficiently strong to withstand the vibration incidental to the motor, 
and greater speeds made possible by mechanical power, the early 
motorcyclist was confronted with two radically different species of 
troubles. While the most important of these were undoubtedly due 
to power plant defects, the annoyances caused by structural weakness 
of frame, wheels and tires were almost as numerous. 

The individual peculiarities of the different machines preclude any 
specific outline of all derangements apt to occur, but a general outline 
of the common troubles may prove of value to the novice rider, 
regardless of the make of machine he rides. Motorcycle troubles may 
be divided into three main classes: those i ncidental to the power plant, 
the derangements of power transmission units and the difficulties en¬ 
countered with the frame structure. In the first-named classification, 
the defects in the engine itself, and the auxiliary groups such as car- 
buretion, ignition and lubrication, may be included. Troubles arising 
from belts or chains, sprockets or pulleys, clutches or two-speed gears 
are properly part of the second class, while frame, wheel, coaster- 
brake, spring fork and tire troubles are assigned to the third classifica¬ 
tion. It is with the first two that we have to deal mostly, because 
there are practically no structural defects in the modern machine, 
therefore of the third classification, we are limited almost entirely to 
tire troubles. 

Classification of Engine Defects. —It is not difficult for one 
familiar with motorcycle construction and operation to make sug¬ 
gestions intended to assist the motorcyclist in locating troubles that 
may materialize with his power plant. The expert, as a rule, recog¬ 
nizes the symptoms of derangement, and usually has no difficulty in 
tracing the trouble to its source by well-known methods. The novice 
is often at loss to know how and where to begin to look for trouble 
and a safe rule for one with little mechanical experience to follow is 


Motorcycle Maintenance , Operation and Repair 513 


to search systematically for derangements and discover the fault that 
the expert would find through its symptoms by a patient process of 
elimination. The motorcycle power plant is really composed of 
several groups, each of which includes a series of distinct components. 
These are related so closely to each other that the failure of any one 
of the devices will affect the operation of the others and thus break 
the continuity of power production. Some auxiliary groups are more 
important than others, because the motor often continues to operate 
for a time after the failure of some essential parts in the group of 
lesser importance. 



Fig. 327.—Combination of Spark Plugs and Priming Arrangements at 
A and B Facilitates Starting on Types of Motors Not Equipped 
With Compression Relief Cocks. Spark Plug With Water-Proof 
Terminal Shown at C. 

While the internal combustion motor is a complete mechanism in 
itself, it cannot operate without some method of supplying inflam¬ 
mable gas to the cylinders and exploding the compressed charge to 
produce power. It will be seen, therefore, that the carburetor and 
ignition systems are really essential parts and that the engine will 
stop at once or work very irregularly if any component of either of 
these auxiliary groups fails to operate as it should. In order to keep 
the motor in operation, it is necessary to keep it cool, which, in a 
motorcycle power plant, is synonymous with supplying lubricant in 






















































































514 


Motorcycles , Side Cars and Cydecors 


proper quantities to the moving parts to reduce friction. The motor 
would run for a time perhaps if lubrication was neglected, but over¬ 
heating and frictional resistance would soon cause cessation of move¬ 
ment. It will be apparent that any defects in the fuel supply or 
ignition systems will make their presence known at once by affecting 
motor action, whereas a defect in the lubricating system might not 
be noticed immediately because the engine would run until it stopped 
because of overheating. 

If a motor be inspected regularly and with any degree of care before 
a trip is commenced, there will be but little danger of serious trouble 
and any skipping or loss of power can be traced to failure of one of 
the components of the auxiliary systems rather than to a defect in 
the power plant itself. Irregular operation is seldom due to the actual 
breaking of any of the parts of the mechanism. Fortunately, de¬ 
preciation, due to natural causes, comes slowly and deterioration of 
any of the mechanical parts always gives sufficient warning so that 
satisfactory repairs may be made before serious troubles occur. One 
of the most annoying troubles, and one that invariably denotes wear 
of the mechanism is continued noisy operation. The sharp metallic 
knocking that is so annoying to both experienced driver and novice, 
when not due to carbon deposits or preignition due to overheating or 
too highly advanced spark, indicates wear at either the main bearings 
or at the upper or lower end of the connecting-rod where the bushings 
may be worn so that considerable play exists between them and the 
shaft they encircle. A grinding noise accompanied by a knocking 
sound generally means that the lubrication system is not functioning 
properly or that the motorcyclist has neglected to inject the proper 
quantities of oil in the engine crank-case. 

Before discussing the failures that may obtain in any particular 
part of the power plant, we will consider a case of engine failure, and, 
for the guidance of the novice, outline the main steps constituting 
a practical process of locating the trouble by systematic elimination. 
If the engine stops suddenly, the two main causes may be either failure 
of the gasoline supply or trouble in the ignition system. A sudden 
stop, when not due to overheating and seizing of the piston in the 
cylinder, which, as we have seen would be evidenced by a pronounced 
knocking long before the overheating became sufficiently great to 




Motorcycle Maintenance , Operation and Repair 51,5 

cause binding, is generally due to a broken wire or a defective spark 
plug. It can be caused also by the stoppage of the spray nozzle in 
the carburetor or the main fuel supply pipe with a particle of foreign 
matter. 

Testing the Ignition System. —In a motorcycle, the simplest 
thing to test, in event of engine failure, is the ignition system, then 
the amount of motor compression, and lastly the fuel supply system. 
If the ignition system is working properly, as may be determined by 
laying the spark plug on the cylinder head and connecting it with the 
large wire leading from the magneto or coil and then pedaling briskly 
to see if there is any spark between the points of the plug, one should 
test the compression, and if this is satisfactory, the carburetor de¬ 
mands attention. The compression is tested by pedaling the engine 
over with the exhaust valve lift down, and if there is a decided resist¬ 
ance to turning at a certain point in the engine rotation, it is safe to 
say that there is no undue loss of gas. 

Let us assume that in making our test with the spark plug on the 
cylinder that there has been no spark between the points of the plug. 
The first thing to inspect is the spark plug itsell, where the following 
points should be carefully considered. First examine the gap between 
the points of the plug. This should be about 1 /64-inch, if a magneto 
system is installed, or about 1 /32-inch, if a spark coil and batteries 
are utilized to produce the spark. With a battery ignition system, 
one should examine carefully all the wires to see that they are tight 
on their terminals, and that none of the wires have become short- 
circuited by burning away of the insulation, which may have been in 
contact with a hot exhaust pipe or cylinder head flange. The vibrator 
or contact spring at the timer may be adjusted poorly, which would 
mean that contact would not be established properly, while the spark 
plug might become short-circuited because of cracked porcelain in¬ 
sulation or carbon deposit. Short-circuiting will also occur in mica 
plugs if the insulator becomes oil-soaked. 

With battery ignition, the source of current should be tested with 
an ammeter to determine if the dry cells have sufficient amperage to 
insure regular ignition. If they indicate less than 5 amperes a cell, 
new ones should be used. A good way to see if current is present at 
the timer is to bridge the insulated contact screw on the timer case 



516 


Motorcycles , Side Cars and Cyclecars 


to the crankcase by means of a screw-driver, with the switch plug in 
place, and observe if there is any spark as the screw-driver end i’s 
rubbed over the engine base. If a spark is present at this point, it is 
reasonable to assume that the trouble is due to defective spark plug 
or to a defective secondary wire leading from the coil to the plug. 

If a magneto be used, it is possible also for troubles to exist at the 
spark plug as previously enumerated, or the ground wire may make 
contact with the metal of the frame before it reaches the cut-out 
switch. The platinum contact points in the breaker box, which is the 
part rocked back and forth as the timer lever is moved, may be out 
of adjustment; the carbon contact brushes that convey the current 
from the revolving armature to the terminal by which the device is 
connected to the spark plug may be broken or not making contact, 
or the insulation of the secondary wires may be defective. 

Common Faults in Carburetion System. —If the trouble is not 
due to the ignition system, and there is good compression in the 
motor, the carburetor demands attention. The first thing to look for 
is to see that there is plenty of gasoline in the tank, as many a novice 
has exerted himself unduly trying to make an engine start.when there 
was no fuel in the container. If the tank is found to hold a sufficient 
supply of fuel, the next thing to do is to make sure that the pipe line 
is clear to the carburetor. This may be ascertained easily by shutting 
off the gasoline at the tank, uncoupling the gasoline pipe at the car¬ 
buretor, and then turning the supply on to see if any issues from the 
pipe. If the gasoline runs out in a full stream when the valve is 
opened, the pipe is clear; whereas, if it trickles out but slowly, one may 
assume that the bore of the tube is oonstricted by becoming dented 
or by dirt. 

One may often determine if the gasoline supply is all right by 
pressing on the little priming pin on the carburetor float bowl unt ; l 
gasoline drips out erf the bottom of the carburetor or the air intake. 
This is called flooding the carburetor. If, on the other hand, the 
carburetor floods continually without the priming pin being depressed, 
it constitutes a defect that will produce other troubles, though not 
always stoppage of the motor. Among other causes that might cause 
engine to stop one should see that the throttle has not become closed 
through the failure of a connecting link or operating wire and that the 


Motorcycle Maintenance, Operation and Repair 5 17 

shut-olf valve in the feed pipe has not jarred closed. The gasoline 
may reach the carburetor all right and yet there may not be enough 
liquid in the float chamber of the device. This would happen if the 
action of the float-controlled needle valve was interfered with by dirt 
or binding, if the float was badly adjusted or if the float valve operat¬ 
ing mechanism was worn unduly in some forms of carburetor. 

Causes of Lost Compression. —Assuming that we have found 
both ignition and carburetion systems to be functioning properly and 
that the motor has no compression, then the trouble is due to some 
condition either inside or outside of the motor. As the external parts 
may be inspected with greater ease, one should look for the following: 
Sticking or bent valve stem, broken valve spring, leak through spark 
plug compression release cock or valve dome, valve plunger stuck in 
its guide keeping valve open, lack of clearance between valve stem 
end and operating plunger or tappet-rod and in very rare instances 
a cracked cylinder head or leaky cylinder head gasket where the head 
is separate from the cylinder. Among some of the defective conditions 
that may exist inside of a motor are: a broken valve, a warped valve 
head, foreign matter under valve seat, piston rings broken or gummed 
in the piston grooves or scored or worn cylinder. 

Causes of Irregular Motor Operation. —If the engine works 
irregularly or skips, the cause may be harder to locate because many 
possible conditions may exist that must be eliminated and checked over 
one by one. In addition to the troubles previously enumerated, a very 
common cause is an air leak around the induction manifold, dirt in 
the carburetor or improper mixture. The gasoline needle may be 
set improperly or may have jarred out of adjustment or the air valve 
spring may have been weakened or broken. The air intake dust 
screen may be so full of dirt and oil that not enough air will pass 
through the mesh. There may be water or sediment in the gasoline 
which would cause irregular operation because the fuel supply would 
vary at the nozzle. 

Where a magneto ignition system is employed, it is seldom that one 
finds defects in the magneto, but when batteries are used just as soon 
as they become weakened the engine will begin to miss fire. Another 
thing that must be done very carefully is adjusting the contact screw 
at the timer as many puzzling cases of irregular ignition with battery 


518 


Motorcycles , Side Cars and Cyclecars 


systems have been corrected by cleaning the oil out of the timer, 
washing the interior out thoroughly with gasoline, and then readjust¬ 
ing the points while the engine was running. Points may be screwed 
nearer together, and if this does not correct the trouble they may be 
separated very gradually. When the proper adjustment is reached, 
the engine will accelerate and run smoothly. (See instructions in 
chapter on ignition for magneto contact breaker adjustment.) 

Conditions Producing Overheating. —Overheating is usually 
caused by carbon deposits or derangement of the lubrication system. 
It is sometimes caused by carburetor troubles as well as insufficient 
oiling. The lubricating system of the average motorcycle is ex¬ 
tremely simple, consisting of a simple hand pump by which oil may 
be injected into the crank-case when desired, and an auxiliary oil feed 
to the cylinders by means of a hand regulated sight feed drip valve 
at the tank. The conditions that most commonly result in poor 
lubrication are: Insufficient supply of oil in engine base, use of poor 
quality oil, clogged oil pipe, defective check valve or worn plunger 
at the pump, clogged sight feed fitting, and if a mechanical oiler be 
employed, a broken pump, or a defective drive. 

Any condition that will cause too rich mixture will also result in 
overheating. These may be enumerated briefly, as follows, too much 
gasoline in the mixture due to improper needle valve regulation, level 
in float chamber too high or auxiliary air valve spring too tight. A 
cork float may be fuel-soaked, or a hollow metal float may leak and 
be full of liquid which increases the weight and causes the carburetor 
to flood. Dirt will also keep the float-controlled needle valve from 
seating, and the level be too high at the standpipe, or, as previously 
outlined, the air screen may become clogged with dust and not enough 
air reach the mixture. If there is an excessive amount of carbon 
present in the combustion chamber and on top of the piston, this will 
also produce overheating and preignition. These deposits should be 
removed from the piston top and combustion chamber wherever 
present. Many cases of lost power which also causes overheating 
have been corrected by merely grinding in the valves to a correct 
seating. Overheating has been caused also by a worn or poorly 
adjusted valve plunger which did not raise the exhaust valve 
from its seat sufficiently, or by altered spark timing which meant 


Motorcycle Maintenance , Operation and Repair 519 

operating the motor on a late or retarded spark or late exhaust valve 
opening. 

Some Causes of Noisy Operation. —There are a number of 
power-plant derangements which give positive indication because of 
noisy operation. Any knocking or rattling sounds are usually pro¬ 
duced by wear in connecting rods or main bearings of the engine, 
though sometimes a sharp metallic knock, which is very much the 
same as that produced by a loose bearing, is due to carbon deposits 
in the cylinder heads, or premature ignition due to advanced spark- 
time lever. Squeaking sounds invariably indicate dry bearings, and 
whenever such a sound is heard it should be immediately located and 
oil applied to the parts thus denoting their dry condition. Whistling 
or blowing sounds are produced by leaks, either in the engine itself 
or in the gas manifolds. A sharp whistle denotes the escape of gas 
under pressure, and is usually caused by a defective packing or gasket 
that seals a portion of the combustion chamber or that is used for a 
joint as the exhaust manifold. A blowing sound indicates a leaky 
packing in crank-case. Grinding noises in the motor are usually 
caused by the timing gears, and will obtain if these gears are dry or 
if they have become worn. Whenever a loud knocking sound is heard, 
careful inspection should be made to locate the cause of the trouble. 
Much harm may be done in a few minutes if the engine is run with 
loose connecting-rod or bearings that would be prevented by taking 
up the wear or looseness between the parts by some means of 
adjustment. 

Valve Removal and Grinding. —The operation of valve grinding 
is a simple one provided that the valve seat is not too badly pitted 
or scored. The first step is to remove the valve from the cylinder, 
which is not difficult with the usual forms of inlet valves, as it is 
merely necessary to remove the dome in which they are housed. To 
facilitate the removal of the exhaust valve, tools such as shown at 
Fig. 328 may be employed to compress the valve spring and permit 
the removal of the pin or key at the bottom of the valve stem. With 
the form shown at A, it is necessary to hold the exhaust valve down 
as the spring is raised, which may be easily done by interposing a 
small block of wood, belt connector, chain link or other object between 
the valve cap and the valve head or by holding the head down against 


520 


Motorcycles, Side Cars and Cyclecars 


the seat with the screw-driver or other tool. With the valve lifter 
shown at B, the hook member supporting the fork or lever that raises 
the spring holds the valve against the seat. If the valve face is badly 
scored or pitted, it may be found desirable to reface that member 
before endeavoring to grind it in. This may be done by a simple tool 
as shown at Fig. 329. A cutting blade is carried by a casting which 
also serves to support the valve stem at one end and a screw at the 
other by which the valve head may be brought in contact with the 
angularly disposed shaving cutter. As the valve is rotated by the 
dog attached to the valve stem, the seat will be trued off to the proper 
angle. Valve grinding consists merely of smearing the face of the 



Fig. 328.—Two Methods of Raising Exhaust Valve Spring to Permit 

Valve Removal. 


valve and the seating with a mixture of emery and oil, and rotating 
the valve against the seat by a screw-driver. The valve is lifted from 
time to time and fresh abrasive supplied every time that the valve 
and its seating are cleaned off with gasoline to see what kind of a 
bearing is obtained. When the valve has been properly ground in, 
it will have a bright ring around the entire circumference of the face 
and the valve seat in the cylinder will show a correspondingly bright 
surface. Among the precautions to be observed, an important one 
is to prevent the emery getting into the cylinder by putting a plug 
or bunch of waste or cloth in the passage between the valve chamber 
and combustion head. It is also best to use a fine grade of emery or 





















Motorcycle Maintenance , Operation and Repair 521 

ground glass and not to bear down unduly on the screw-driver or 
grinding tool. It is better to oscillate the valve than to turn it around 
completely because when the valve head is moved a portion of a 
revolution and back again it is not so apt to roll the abrasive up into 
a ball that may cut ridges in the valve seat. 

Removing Carbon Deposits.— If the motor is of a detachable 
head form, it is a comparatively simple matter to remove the com¬ 
bustion head which will expose the piston top as well as the com¬ 
bustion chamber. The carbon deposits, which are a fertile source 



Fig. 329.—Simple Tool Used in Refacing Valve Seat. 

of trouble, may be removed by positive mechanical means, such as 
indicated at Fig. 330, A, in which a screw-driver, chisel or scraper is 
employed to scrape them off. As the combustion head is removed, 
it will not be difficult to relieve it of carbon deposits in the same 
manner. If a one-piece cylinder is employed, that member may be 
removed, as shown at Fig. 331, which will expose the piston top and 
the combustion chamber interior for mechanical scraping. 

A new process of carbon removal which is meeting with success 
is shown at Fig. 330, B. This calls for the use of a small torch burning 




























522 Motorcycles , Sicfe Cars and Cyclecars 

ordinary gas or an ordinary match to start combustion, and another 
member that will supply oxygen to the interior of the combustion 
chamber. The stream of oxygen permits combustion of the deposit 
and the carbon is burnt out at all points where the flame touches, 
passing out of the cylinder in the form of a gas, and leaving only a 
fine residue or dust in the combustion chamber, which is blown out 
with the exhaust as soon as the engine is started. As the application 
of the oxygen process does not necessitate dismantling the engine, it 
may be used to considerable advantage, especially with the one-piece 
cylinder construction. 

Instructions for Running De Luxe Motors. —As the Spacke 
motors are so generally fitted to motorcycles and cyclecars, the 



Fig. 330.—Methods of Removing Carbon Deposits From Piston Top 

or Combustion Chamber Interior. 


following instructions, furnished by the makers, may prove of value 
to the riders using this well-known power-plant equipment. 

Any motorcycle motor, by reason of its relatively light weight and 
high speed of operation, requires a consistent amount of care to insure 
long life and satisfactory operating service. Care should be exercised 
to see that all adjustments are properly taken care of, and that the 
motor is at all times supplied with the proper amount of lubricating 
oil. Oil is always cheaper than repairs. Keep the motor clean. 
Avoid racing motor when using the free engine clutch or when running 
on stand, and prevent untimely depreciation. Watch oil tank and 
sight feed to make certain that the motor is getting its supply of oil. 

Keep spark fully advanced and regulate speed by the throttle, 









Motorcycle Maintenance , Operation and Repair 5 %3 

except when ascending a bad hill, spark should be retarded enough 
to prevent motor from knocking. Avoid using too rich a mixture, 
as the unburned gasoline carbonizes in cylinder. After each 500 
miles is ridden, old oil should be drained from crank-case, and latter 
should be flushed out with kerosene. Refill crank-case with oil to 
bottom of oil window before running again. 

De Luxe motors should always be lubricated with a sight feed drip, 


Fig. 331.—Accessible Design of Rudge-Multi Motorcycle Permits the 
Removal of the Cylinder Without Disturbing Position of Engine 
Base in Frame. 

fastened to oil tank and connected to ball valve between the cylinders 
on the twin, and behind the cylinder on the single. If a hand oil pump 
is provided, it should be connected to the drip feed tube just above 
ball valve, by means of a “Y” or “T” connection. The sight feed 
should be set to drop about 8 drops per minute for the single-cylinder 
and about 12 drops per minute for the twin-cylinder motor. How¬ 
ever, the amount varies with the quality of oil and the speed, and the 








5£4 Motorcycles , Side Cars and Cyclecars 

rider should make sure that the motor is always getting enough oil, 
but not so much as to cause excessive smoking. Cap over inlet valve 
rocker arm should be removed occasionally, and the space packed with 
hard grease and graphite. 

To facilitate starting in cold weather, motor may be primed by 
removing the rocker arm cover screw nearest the carburetor, and 
a small amount of gasoline injected into the screw hole. 

Clearance between push rods and valves should be kept about .007 
inch, which is about equal to two thicknesses of newspaper. This will 
insure quiet running and correct timing. 

To time valves, turn crankshaft forward until piston arrives 7 /16 
inch from bottom of stroke, and hold in this position. Turn cam shaft 
outward from motor until exhaust push rod is lifted against valve 
stem. Replace crankshaft timing pinion, so that mark corresponds 
with mark on cover, when pinion is in place. Replace nut and cotter. 
As the spiral teeth of the pinion cause it to rotate to the left while 
being pushed into place, it must be started a quarter turn to the right 
of its correct final position. 

To set magneto after valves are timed, turn crankshaft forward 
until piston arrives % inch from top of compression stroke. Set mag¬ 
neto timing lever to full advance; turn armature toward motor until 
interrupter contacts start to separate. Replace magneto drive gear 
on cam-shaft, so that mark on gear corresponds with mark on cover 
when gear is in place. Replace nut and cotter. This gear rotates to 
the left while being pushed into position and must be started 1 /6 turn 
to the right of its correct final position. On twin motors, the rear 
cylinder should be used for both valve and magneto timing. Remov¬ 
ing cover from crank-case disturbs the timing of the valves, neces¬ 
sitating retiming, but does not affect the magneto setting, which is 
onty disturbed when magneto is removed from pad. Magneto on the 
twin is marked I and II just above cable terminals. I should be 
connected to rear cylinder, and II to front cylinder. 

It is important that the nut holding driving pulley or sprocket on 
crankshaft be kept tight, as this nut holds left fly-wheel in position. 
Special wrenches are furnished with each motor. 

Defects in Power Transmission Elements. —If the drive is not 
positive when chains are employed, the trouble is invariably due to 


t 


Motorcycle Maintenance , Operation and Repair 5%5 

a slipping clutch or compensating sprocket which may be easily 
remedied by adjusting these devices. If chains break frequently, it 
is because they are either worn unduly, sprockets are not in proper 
alinement, or the sprockets have depreciated to such a point that the 
teeth are hooked and do not permit the chains to ride smoothly over 
them. Chains should be kept clean and thoroughly lubricated in 
order to obtain silent driving. Lubrication does not consist of indis¬ 
criminate application of oil over the chain surface, but should be done 
by removing the chains, cleaning them thoroughly in gasoline or 
kerosene, and then boiling them in tallow or a mixture of grease and 
graphite. After the chains have been allowed to soak in this hot 
mixture, they are taken out and the surplus lubricant wiped off the 
outside. Oil on the chain surfaces merely serves as a basis for ac¬ 
cumulations of dirt which act as an abrasive and produces rapid wear¬ 
ing of both chains and sprockets. 

Testing for Chain Alinement. —There are two ways in which 
alinement may be at fault. The sprockets may be in line, but the 
shafts may be out of parallel. On a well-designed machine, this 
should not happen, but cases have been known. The second possi¬ 
bility is that the shafts may be parallel, but one sprocket further in 
or out on the shaft than the other. 

In order to discover if the alinement is correct, the inside of the 
side plates of the inner links of the chain should be examined after 
the chain has been in use some little time. If the side plates on one 
side of the chain are worn much more than those on the other, with 
ridges or shoulders cut in them by the wheel teeth, the probability 
is that one of the shafts is a little out of parallel. Should both sides 
of the chain be unduly worn and cut, probably one wheel is further 
out on its shaft than the other. A straight edge, or even a piece of 
string stretched tightly across the faces of both wheels, will often 
indicate the error. Generally speaking, errors in alinement are best 
corrected by the expert, i. e., the machine should be taken to the 
agent for examination. 

How to Adjust Chains. —If the chain is too slack, it is apt to 
“whip,” which intensifies the wear and tends to break the rollers. 
If, on the other hand, it is too tight, a crushing effect is produced on 
the rollers, and the whole chain is strained unduly. A chain should 


52f> Motorcycles , Sfofe (7ar.<? and Cyclecars 

be adjusted, and kept adjusted, so that it can be pressed down with 
the finger from }/$ inch on the short drive from engine to counter¬ 
shaft, to, say, }/2 inch on the back chain. 

Adjustment of the first reduction drive is generally provided for 
by an eccentric on the countershaft, or by sliding the gear box. The 
slack in the back chain is taken up in the same manner as on the 
pedal cycle by drawing back the rear wheel. Of course, the tension 
of all chains should be looked to at the same time. 

Slipping Belt Drive. —Flat belt drive is well thought of but has 
the defect of slipping at times. It is imperative that the belt be kept 



Motor Cycle Chain Poller with. Fly Not Chain Rivet Punch* 


Fig. 332.—Tools Used to Facilitate Repair of Motorcycle Drive Chains. 

soft and pliable at all times with applications of neatsfoot oil, and 
that the lagging on the small pulley be maintained in proper condition.. 
When the lagging wears off, the belt will not have sufficient adhesion 
with the small metal pulley, and slipping is unavoidable. Various 
special laggings composed of woven asbestos materials impregnated 
with rubber are marketed at the present time which give much more 
satisfaction than leather, as they are more enduring and have a greater 
degree of friction. The V-belt transmits power positively and only 
slips when the pulleys are worn so that the belt does not contact 
properly with the pulley sides. The design of the V-belt is such 
that it has a certain wedging action in the pulley and is not apt to 






































Motorcycle Maintenance , Operation and Repair 527 


slip &s is the flat belt. If the clutch is at fault as is the case if the belt 
or pulleys are not worn unduly, it can be taken up until it transmits 
power without slipping. 

Care of Leather Belts. —Clean your belt thoroughly and often, 
once a week, or at least after every hard run. Carefully scrape off 
all dirt or sand. 

After each cleaning, apply motorcycle belt dressing. This dressing 

will increase the life and 
efficiency of your belt— 
keep it soft and pliable, 
and prevent unnecessary 
slippage, which will wear 
out any belt. 

It is important that 
the screws in pulley lag¬ 
ging do not project; if 
they do, they will cut the 
belt and shorten its life. 

Be sure to release the 
idler when machine is 
not in use, and apply 
carefully when in service 
—this warrants minimum 
stretch of belt, and en¬ 
ables it to retain its elas¬ 
ticity and wear longer. 

Care of Wheels. —The 
important point to ob¬ 
serve in regard to the wheels is that these are adjusted so that they 
revolve freely. If the cones of the hubs are screwed up too tightly, 
the ball-bearings will have considerable friction and will wear out 
rapidly. The hub bearings should always be kept properly lubricated, 
and the cones should never be tightened up beyond the point where 
the wheel will revolve freely and yet have no side-play or shake. 
Where the drive is through the hub, as is the case in all chain-driven 
machines, one should inspect the rear wheel carefully from time to 
time for loose spokes. With a belt-driven machine, this precaution is 



Fig. 333.—The Noonan Chain Bath, a Handy 
Device for Cleaning Motorcycle Drive 
Chains. 














52 8 


Motorcycles , &7/e Cars and Cyclecars 


not so necessary because the power is applied to a large belt pulley 
attached directly to the rim and not through the medium of the hubs 
anclspokes. The front hub, if properly adjusted, is not apt to give any 
trouble, but the rear wheel which has a coaster-brake hub needs 
more attention. It not only demands more oil and careful adjustment 
of the hub bearing, but the braking mechanism must be looked at 
from time to time to make sure that the brakes will function properly 
when needed. If the brake does not engage promptly, it indicates 
that the brake end is filled with an accumulation of old, gummed-up 
lubricant. If the brake takes hold too quickly, it indicates lack of 
lubrication in brake end. If hub runs hard, it indicates that adjust¬ 
ing cone is too tightly screwed in; if hub wabbles, it means that 
bearings are adj usted too loosely. If forward pedaling does not engage 
hub and rotate it promptly or back pedaling does not apply brake 
positively, examine transfer spring to see that it is not broken and 
that it is in place correctly. 

Common Defects in Clutches. —Considering first the member of 
the transmission system that will affect the efficiency of the entire as¬ 
sembly when deranged, it will be we)l to discuss the troubles common 
to the various types of clutches. The defective conditions that most 
often materialize are too sudden engagement which causes “grabbing,” 
failure to engage properly, slipping under load, and poor release. 
Clutches utilizing a leather facing will cause trouble after a time, 
because of natural wear or some defect of the friction facing. The 
leather may be charred by heat caused by slipping, or it may have 
become packed down hard and have lost most of its resiliency. The 
clutch spring may be weakened, or broken; this will cause the clutch 
to slip even if the leather facing of the cone is in good condition. 
The two troubles usually met with by the motorist are harsh action, 
as one extreme condition, and loss of power through slippage as the 
other. 

When a cone clutch engages too suddenly, it is generally caused by 
the surface of the leather lining becoming hard and not having suffi¬ 
cient resiliency to yield to some extent when first brought into fric¬ 
tional contact. To insure gradual clutch application, the facing 
should be soft and elastic. If the leather is not burned or worn un¬ 
duly, it may often be softened by rubbing it with neatsfoot oil. Kero- 


Motorcycle Maintenance, Operation and Repair 529 

sene oil is often enough to keep the clutch leather pliable, and it 
possesses so little lubricating value that the clutch members are not 
liable to slip because of a reduced coefficient of friction such as often 
caused by the application of more viscous lubricants. Kerosene has 
other advantages, among which may be mentioned quick penetration 
of the leather and not collecting grit or gumming. 

When a cone clutch slips, it is usually due to a coating of oil on the 
frictional material that decreases the value of the coefficient of friction 
to such a point that the pressure of the clutch spring is not enough to 
maintain sufficient frictional contact between the male and female 
members to insure driving. The remedy for this condition is to absorb 
the surplus oil by rubbing a small quantity of fuller's earth into the 
leather surface. When the clutch cone is in place, it is not easy to 
reach the surface of the leather, so the first step would be to disengage 
or release the clutch and to place enough of the fuller's earth on a 
piece of paper or card so it can be sprinkled into the space left between 
the male and female members when the former is properly released. 
Borax is sometimes recommended for the same purpose, and when the 
earth or borax is not available the carbide dust or lime residue from 
the acetylene gas generator may be used to advantage. If slipping is 
caused by weakening of the clutch spring, it may be prevented by 
substituting springs of proper strength or by increasing the degree of 
compression of the weak springs by the means of adjustment often 
provided for the purpose. 

Another annoying condition that sometimes obtains when a cone 
clutch is used is spinning or continued rotation of the male member 
when clutch spring pressure is released. This may be the result of 
natural causes, but it is sometimes caused by a defect in the clutch 
mechanism. If the bearing on which the cone revolves when dis¬ 
engaged seizes because of lack of lubricant the male member of the 
clutch will continue to rotate even when spring pressure is released. 
The ball-thrust bearing employed to resist spring tension may become 
wedged by a broken ball, and this will cause the rotation of the crank¬ 
shaft to be imparted to the cone member through the spring, which 
must turn with the crankshaft instead of remaining stationary, as 
would be the case if the ball-thrust bearing was functioning properly. 

On those motorcycles fitted with multiple-disc clutches, the same 


530 


Motorcycles , Side Cars and Cyclecars 


troubles may be experienced as with other types. If a multiple-disc 
clutch does not release properly, it is because the surfaces of the plates 
have become rough and tend to drag. The plates of a multiple-disc 
clutch should be free from roughness, and the surfaces should always 
be smooth and clean. Harsh engagement also results by the absence 
of oil in those types where the discs are designed to run into an oil 
bath. Spinning or continued rotation of a multiple-disc clutch often 
results from seizing due to gummed oil, the presence of carbon or 



Fig. 334.—Diagram Showing Construction of Simple Puller for 
Removing V Pulleys or Sprockets From the Taper on End of 
Engine Crankshaft. 


burned oil between the plates and sometimes by a lack of oil between 
the members. When a multiple-disc clutch slips, it is generally caused 
by lack of strength of the clutch springs or distortion of the plates. 
To secure the best results from a multiple-disc clutch, it is imperative 
that only certain grades of oil be used. If one uses a cheap or inferior 
lubricant, it will gum and carbonize, because of the heat present when 
the plates slip or it will have such viscosity that it will gum up between 













































































Motorcycle Maintenance , Operation and Repair 531 

the plates. Most authorities recommend a good grade of light or 
medium cylinder oil in multiple-disc clutches where lubricant is re¬ 
quired. In some cases, faulty multiple-disc clutch action is due to 
“brooming/’ which is the condition that exists when the sides of the 
keyways or the edges of the disc become burred over and prevent full 
contact of the plates. Clutch plates with friction facing, such as 
Raybestos, are intended to be run without lubricant, and will be apt 
to slip if oil is put in the clutch case. When the frictional material 
wears, it must be replaced with new. New facings or discs may be 
obtained from the motorcycle builder much cheaper than from other 
sources. 

Derangements in Change Speed Gearing. —As previously ex¬ 
plained, the simplest form of gearing to obtain various speed ratios 
in cyclecars is the friction-disc type. Failure to drive properly may 
result from excessive oil on either the face of the driving disc or the 
periphery of the driving wheel, lost motion, wear or spring at various 
points in the operating mechanism, or deterioration of the surfaces of 
either driving discs or driven wheel. If trouble is experienced in a 
friction transmission, the first point to inspect is the condition of the 
friction surfaces. If excessive deposits of oil have caused slipping, it 
should be thoroughly removed with gasoline and the surface of both 
disc and wheel sprinkled with talc powder. If the face of the alumi¬ 
num alloy driving disc is grooved or roughened, slipping is inevitable 
until the disc is refaced absolutely true. The strawboard fiber friction 
band of the driven wheel may “broom” out, and this will cause 
slipping because the surface is not true. As a general rule, the fiber 
ring of the friction transmission should be renewed after it has been 
used from 4,000 to 5,000 miles. Wear at the countershaft bearings 
will produce a tendency for the driven wheel to crowd toward the 
center or edge of the driving disc, depending upon the relation of the 
actual line of contact with the theoretical contact line drawn through 
the disc. Lost motion or spring in the parts serving to engage the 
friction surfaces will cause slipping because the degree of pressure 
necessary to secure the frictional adhesion required between the 
members to secure positive driving will be reduced. 

The chief trouble with a planetary transmission of the type used on 
motorcycles and cyclecars is caused by slipping clutch bands. These 


532 


Motorcycles , Side Cars arid Cycle cars 


are provided with adjustments that can be tightened in case of wear, 
and should grip positively. If either the slow or reverse bands are 
adjusted too tight, they will bind on the drums and produce friction, 
which, in turn, will decrease the efficiency of the drive. Noisy action 
of planetary gearing is usually caused by lack of lubrication or ex¬ 
cessive wear in the gearing. If the oiling is properly taken care of 
this condition will be practically eliminated. Sometimes the high¬ 
speed clutch may slip, but most planetary gears are provided with 
adjustable clutches so any wear may be readily taken up. 

When sliding-gear or shifting clutch transmissions are used, the 
most common defect is difficulty in shifting gears and noisy operation. 
The trouble met with in gear shifting is usually caused by the edges 
of the teeth of the shifting members having burred over so that they 
do not pass readily into the spaces between the teeth of the gears they 
engage with. Another cause of poor gear shifting is deterioration of 
the bearings which may change the center distances of the shafts to 
a certain degree and the relation of the gears may be changed relative 
to each other so they will not slide into mesh as freely as they should. 
Noisy operation is usually due to a defective condition of lubrication, 
and if the gears are not wo m too much it may be minimized to a large 
extent by filling the gear case with oil of sufficient consistency to 
cushion the gear teeth and yet not be so viscous that it will not flow 
readily to all bearing points. A difficulty in shifting is sometimes due 
to binding in the control levers or selective rods, and these should 
always work freely if prompt gear shifting is required. If considerable 
difficulty is experienced in meshing the gears and the trouble is not 
found in the gear-set, it will be well to examine the clutch to make sure 
that the driven member attached to the gear-set main shaft does not 
“spin” or continue to revolve after the clutch is released. 

Adjustment of Brakes. —The means of adjusting brakes may be 
easily ascertained by inspection. If brakes do not hold properly, and 
the friction facing is in good condition and free from oil, the failure 
to grip the drum is probably due to wear in the operating leverage. 
On some form of brakes, notably those which are expanded by a cam 
motion, compensation for wear of the brake shoes is often made by 
shortening the rods running from the brake to the operating lever. 
External brakes are usually prov ided with an adjustment on the brake 


ENGINE 

WILL 

NOT 

START 


b 


Carburetter 
floods on 
depressing 

float needle 


-Spark at plug- 


—Spark at terminal - 


-No spark at plug- 


L —No spark at terminal — 


-Breaker arm free- 


.No petrol at_ 

carburetter 


-spark too weal 
under compr 
-Short on plug, 
or lead. 
-Faulty plug. 
-Sooted plug po 
-Weak spark. 
-Short circuit. 
-Breaker arm st 
-Dirty platinum 
-Faulty contact; 
-Failure in mag 
sulation. 
-Broken carbon 
-Controls stick! 
-Incorrect timir 


—Air leakage. 
-Petrol tap cIos< 


-Petrol tap open- 


- Pipe clear - 


-Choked pipe. 
-Dirt in jet. 
-Air lock In tan 
-Float needle st: 


ENGINE 

RUNS 

IMPER¬ 

FECTLY 


-Lacks power- 


-Constantly- 


- Controls In order- 


-At intervals - 


Engine knocks- 


~Misses fire- 


-Spark irregular- 
—Spark regular— 


-Fails on hills- 


-Correct gear ratio- 


-Engine clean- 


- Controls out of 

- Poor compressi 
—Valves need gr 
—Valve springs ’ 
—Stretched exha 
-Choked silence 
-Incorrect valve 
-Gear too high. 
-Bad air adjusti 

- Obstruction ir 

pipe. 

-Excessive car 
posit. 

-Partial obstruc 
petrol. 

- Carburetter too 
-Sticking valve 
-Pre-ignition. 

- Overheating. 
-Sooted plug. 
-Dirty breaker ] 
-Occasional shoi 
-Mixture too we 
—Water in petra 
-Starved carbur 
-Too high a gea 
-Engine dirty. 
-Stretched valvi 

- Sooted plug. 
-Ignition too fai 

- Too much air. 


ENGINE 


STOPS 


— Spark at plug points- 


- Petrol 


- Compression- 


-Carburetter working- 


Carburetter 'not-working 


-No comprossion- 


|—No spark at magneto- 


*-No spark at plug points 


- Breaker arm free - 


-No petrol. 
-Broken valve re 
on seat. 

- Broken valve sj 
-Controls not wi 

- Overheating. 
-Insufficient lubi 
-Air leakage. 
-Stripped timing 
-Choked jet or p 
-Punctured float 
-Flooded float ch 
-Air lock. 
-Binding needle. 
-Broken valve. 

- Broken piston r 
-Piston ring slot 
-Piston rings gu 
-Valve sticking 
-Broken piston,c 

rod, or crank 

- Pitted valve fac 
. Sticking break; 

- Platinum points 

attention. 
-Broken brushes 

- Failure in cond 
-Internal shortlr 

wet. 

-Failure of insul 
-Dirty contacts., 

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External brakes are usually prov ided with an adjustment on the brake 






















































Motorcycle Maintenance , Operation and Repair 533 

band, which permits one to draw the ends of the band closer together 
and take up much of the lost motion between the band and the brake 
drum. After the brakes are adjusted, it is well to jack up the machine 
to make sure that the wheel turns freely and that there is no binding 
between the brake members and the drum on the hub. If the brake 
is adjusted too tightly the friction will cause heat after the motorcycle 
has been run a short distance, and this increase in temperature is a 
very good indication of power loss by friction between the brake and 
the drum. If the brakes are not adjusted sufficiently tight, a full 
movement of the pedal or hand lever will prove inadequate to apply 
the brakes tight enough to stop rotation of the wheels. When the 
friction facing is worn, it must be renewed. Slipping of metal-to-metal 
brakes is often due to accumulation of gum or old oil. This is a 
common fault with multiple disc types. If a disc brake heats up, the 
surfaces of the plates are rough and do not pass each other freely. 

Repairing Inner Tube Punctures. —The first thing to do is to 
locate the hole through which the air is escaping. If it has been 
caused by a nail or other large object, it may be easily found by 
examining the tube, but in some cases it may be a very small puncture 
that cannot be discovered readily. After removing the inner tube 
blow it up until it is distended to its normal size. Do not put enough 
air in the tube to stretch it as if the pressure is too high it may enlarge 
the hole. If a bucket or trough of water is at hand, immerse the tube 
in the water a little at a time, at the same time slightly stretching the 
tube. If this is done carefully, air bubbles will be seen rising from 
the leak, no matter how minute it is when the injured portion of the 
tube is under water. If it is impossible to get enough water to im¬ 
merse the tube, dampen the hand and pass it along the tube surface. 
The wet hand is very sensitive to even the slightest air current, and 
the leak can be found very readily in this manner. Another way to 
locate a leak is to blow the tube up and then pass it close to the ear, 
revolving it slowly so that all parts of the tube are passed before it. 
The leak will be evidenced by a hissing noise which is in proportion 
to the size of the leak. A good way of marking the leak positively 
is by means of an indelible pencil which will leave a mark on the rubber 
when moistened that will not come off. 

A piece of sandpaper or emery cloth is usually provided in a repair 


534 


Motorcycles , Side Cars and Cyclecars 


pg 

kit, and with this all of the gray deposit from the rubber should be 
cleared from an area around the puncture, somewhat larger than the 
patch to be fitted. This talc and powdered rubber may also be 
washed off with gasoline or scraped off with the blade of a jack-knife 
if the sandpaper is not available. It will be well to treat the surface 
of the patch in the same manner, and to roughen up the clean surfaces 
of both tube and patch with sandpaper or a wire scratch brush. A 
light coat of cement is then applied to both patch and inner tube, and 



Fig. 336.—Conventional Forms of Motorcycle Outer Casings That 
Have Been Generally Applied. A—Corrugated Tread. B—Studded 
Tread. C—Combination Tread. 


is allowed to dry for five or six minutes. Then the operation is re¬ 
peated and more cement is spread over the surface. This is also 
allowed to dry, and, when the surface is sticky, the patch is pressed 
firmly in place and held in position by a clamp or some other means 
that will produce pressure. The patch should be allowed to set for 
ten or fifteen minutes before replacing the tube. Powder the patch 
and tube freely with soapstone or talc to prevent the tube sticking 
to the casing. 







Motorcycle Maintenance , Operation and Repair 535 

It is well to examine the casing before replacing the tube to be sure 
that the cause of the puncture is removed. This may be done by 
passing the hand around on the inside. The puncturing object often 
becomes imbedded in the rubber, and while it is not visible from the 
outside it may stick through the casing and protrude on the under 
side. Temporary repairs to the casing should be made from the 
inside. A piece of fabric three or four times the width of the hole 
and long enough to reach from edge to edge of the casing should be 
cemented in place. This is done by cleaning the lining of the casing 
and applying two coats of cement, while the prepared fabric which is 
already coated with rubber should be wet with a little gasoline before 
it is pressed in place in the inside of the shoe. 

Outer Casing Repairs. —If a tire, even when well inflated, strikes 
a sharp stone at high speed this is apt to tear off a portion of the 
tread, and. often injures several plies of the fabric. This is called a 
stone bruise and weakens the shoe to some extent, depending upon 
the amount of material removed from the casing or the depth of 
penetration and its location. The shoe is weakened much more if 
the tread is damaged than if the side wall is scraped. If a stone 
bruise or other cut penetrating the tread is neglected, sand or road 
gravel is apt to work into the tire as it revolves and this material soon 
accumulates between the tread and fabric or between the layers of 
fabric until it forms a protuberance of some size. This is called a 
sand blister. The action of this compacted material is to break down 
the layers of fabric between it and the tube and the casing inevitably, 
blows out if the defective condition is not remedied. 

Rim cutting is usually caused by running the tire flat or not inflated 
sufficiently. It is sometimes due to rusty or rough rim edges or to 
poorly fitting rims or improperly designed beads on the tire casing. 

Cuts in casings allow water to enter and rot the fabric even if they 
are not sufficiently large to weaken the shoe appreciably. They may 
be easily filled up by using special repair pliers to spread out the 
rubber and open the cut sufficiently to clean it out with gasoline and 
insert special cement and repair gum. When the pliers are with¬ 
drawn, the rubber closes around the repair material, and when the gum 
hardens it fills the hole thoroughly. 

Weakened casings can be used for some time by the insertion of 


,530 


Motorcycles , Side Cars and Cyclecars 


a reliner of fabric which strengthens it and presents a solid, unbroken 
surface for the inner tube to bear against. An outer casing or leather 
protector may also be employed. 

A good temporary repair of a burst casing can be made by using 
an inside and an outside blowout patch. A new inner tube should 
never be inserted in a burst casing without first taking some pre¬ 
cautions to close the hole or rent, both from inside and outside, or the 
tube will blow through at the weakened spot of the shoe before it 
has been in use for any length of time. The inner patch is composed 
of several layers of frictioned fabric (fabric impregnated with rubber 
compound) and the larger sizes are provided with hooks which engage 
the rim if a clincher type is used. It is from six to eight inches long 



Fig. 337.—How to Remove Motorcycle Tire Outer Casing Without 

Pinching Inner Tube. 


for small tires. The strength of fabric used also varies with the size 
of the tire the patch is made for. This is placed in the casing in such 
a way that the rent comes at a point approximately at the center 
before the inner tube is inserted. After the casing is replaced and is 
partially inflated, the outer shoe or patch is laced tightly in place 
around tire and wheel rim and then inflation of the tire is completed. 
A repair made in this manner is reliable enough so the tire remains in 
service for some time without attention, though the temporary 
patches should be replaced by a permanent repair at the earliest 
opportunity. Winding the casing with tire tape will help if no blow¬ 
out patch is available. 













Motorcycle Maintenance , Operation and Repair 537 

To repair a badly cut or rent outer casing, it is usually necessary to 
rebuild the casing at the injured part. The injured fabric is cut out 
and replaced with new, and new tread rubber is also applied to the 
outside of the casing. The layers of fabric or rubber are well cemented 
with special material adapted for curing, and are thoroughly vulcan¬ 
ized together and amalgamated with the remainder of the shoe. In 
cutting out the old fabric, the first inside layer is cut out at least six 
inches each side of the blowout. The next layer is stripped off for 



Fig. 338.—Defining Methods of Folding Inner Tubes for Transpor¬ 
tation. 


five inches each side of rent, then two or three of the succeeding layers 
are taken off for the same distance say four inches each side of the 
injury. In replacing the layers with new fabric, it is cut to fit the 
steps left when the injured material has been removed. Building up 
in this manner makes a much stronger repair than just replacing the 
injured material would, because each layer applied reinforces the 
others beneath it, and when the last ply is in place and all firmly 


























































538 




Motorcycles , Side Cars and Cyclecars 


Fig. 339._Showing Forms of Rims That Have Been Used in Motor¬ 

cycle Wheel Construction and Sizes of Tires Adapted for 
Them. 


NEW STYLE 1913 
Blue Streak Tires 
28 x 1 3 A Plain Tread 
28 x 2 Plain Corrugated or 
Studded Tread 


Blue Streak Tires 
28 x 2/4. Corrugated 


28 x 2 3 A 28 x 2 3 A 

28 x 3 28 x 3 


OLD STYLE 
Studded Corrugated 

26 x 2/4 
28 x2% 23 x 2V* 

26 x 214 26 x 2V2 

28x214 28 x 2^4 

29 x 2 3 4Tandem 29 x 2% 
Tandem 


28 x 2.14 28 x 2J4 

26 x 2.14 26 x 2 V 2 . 

28 x 2 V 2 28x214 

29 x 2% Tandem 29 x 2 3 4 
Tandem 


Double Clincher 














Motorcycle Maintenance , Operation and Repair 539 


joined together by the curing process, the shoe is practically as good 
as a new one. 

Improper inflation is responsible for much of the tire trouble that 
comes to motorcyclists. Under-inflation makes rim-cutting easy. 
The continued flexing of partially filled tires tends to break down the 
fabric in the side walls. Careful, scientific tests—trials of actual 
service—have shown conclusively the air pressure best suited for each 
tire size. The following table is offered by the Goodyear Company: 


Regular Tires. 

234 inches, 30 pounds 
2J/2 inches, 32 pounds 
2^ inches, 35 pounds 
3 inches, 40 pounds 


Racing Tires. 

1 inches, 45 pounds when cool 

2 inches, 50 pounds when cool 
234 inches, 55 pounds when cool 


Advice to Purchasers of Secondhand Motorcycles. —In the 

present state of efficiency of motorcycle manufacture, no machine 
can be said to be worn out for several years, but styles change very 
rapidly and there will always be those who want to be right up to 
the minute regardless of the expense entailed. In consequence, there 
is on the market to-day a large number of excellent second-hand 
machines. But in no other business, except perhaps the gold-brick 
and green-goods line, is it so easy for the novice to make a poor 
bargain. It is very difficult to tell the real condition of a motorcycle 
at a glance, and even a trial cannot always be depended on. Further¬ 
more, a machine may run nicely for a few miles, and yet, in a few 
weeks, require endless repairing. On the other hand, one often finds 
motors which, through bad handling or lack of tuning, run very badly 
or not at all, though for a small outlay of time and money, properly 
applied, they could be made to give excellent results. 

The first thing to consider is whether the machine in question is 
worth purchasing at all. With the large selection offered one can 
afford to be particular; there are some faults which it is not worth 
while to attempt to remedy. The question of age resolves itself en¬ 
tirely into a question of make, for, if the machine was a good one in 
the beginning, it will be good much longer than one which was 
originally of a lower grade; but the matter of design is also important. 
Be sure its maker is still in business. A machine of short wheel-base, 


540 


Motorcycles , Side Cars and Cyclecars 


high saddle, high-hung engine, and short handle-bars will never be 
comfortable, and it would be wiser to wait for an opportunity to 
obtain one of a more modern build. Transmission must also be con¬ 
sidered. The type is entirely a matter of personal preference; but 
block chains, roller chains too small for their work, a narrow flat belt 
with an idler, “V” pulleys not cut to twenty-eight degrees, or too 
small an engine pulley, can never be made to give efficient service. 
A cracked frame lug, cylinder, crank-case, or piston, or a buckled 
wheel, also mean repairs that had better be left for the buyer with 
mechanical skill. 

Not less important is the condition of the engine. This is the 
heart of the machine, and, if it has been seriously injured, the cycle 
will be part of the repair shop furniture for some time to come. Jack 
up the rear wheel, and stand on the pedal with the exhaust valve 
dropped. A high compression engine in good condition will hold your 
weight almost indefinitely in this manner, but if the pedal does not 
fall for several seconds, the cylinder and rings may be considered to 
be in good condition. If it goes down rapidly, the engine should 
be examined further. Have the cylinder taken off and run your 
finger carefully all over the inside surface. If you find any cuts, 
scratches, grooves, or rough spots, it must be replaced. If, however, 
it is all bright and smooth, you may turn your attention to the rings. 
Examine carefully the surface which rubs against the cylinder. It 
should be all brightly polished, but there will probably be dark spots. 
If these spots are very frequent, you had better steer clear, but if 
only a few it simply means new rings. First, however, be sure that 
you can obtain new rings for that particular make of model, as it is 
an expensive job to have them especially made. 

While you have the cylinder off, glance at the bearings. Run off 
the belt or remove the chain and try to move the pulley or engine 
sprocket up and down. A tiny amount of play is to be expected here, 
but if it is at all great, new main bushings will be needed, the cost of 
which must be added to the price you are to pay. The same is true 
of the crank and wrist-pin bushings. The former can be tested by 
moving the connecting-rod up and down while the pulley is held still, 
and the latter by holding the connecting-rod with one hand and 
moving the piston up and down with the other. If the motor is a 


Motorcycle Maintenance , Operation and Repair 541 

ball bearing form and the bearings are worn, remember that these 
cost money, in fact, several times as much as plain bearings. Better 
let someone else buy them. 

Next to motor repairs the tires are probably the most expensive 
parts to renew. These are often overlooked in buying a second-hand 
mount, because they can be obtained anywhere, but it should be 
remembered that they cost a great deal. A flat tire means a puncture 
or rotten tube, although the owner may tell you that he just let it 
down “to keep it from stretching.” Chains or belts are also large 
items and their condition should be noted. Do not forget to examine 
the sprockets, as, if they are worn, it will be useless to replace the 
chains unless they are replaced also. Damaged pedaling gear, broken 
brake, dented tanks or rims, run-down batteries, bent spokes, and 
broken mud-guard stays or control levers, are of less importance, as 
they are easily repaired, but they should all be looked for and taken 
into consideration. 


INDEX 


Page i 

Action of Friction Clutch.287 

Action of Two-Cylinder Motor... 92 

Adjustment of Brakes.532 

Advantages of Belt Drive.340 

Advantages of Chain Drive.350 

Advantages of Mechanical ValveslTl 

Advantages of Motorcycle. 18 

Advantages of Multiple-Cylinder 

Motors .120 

Advice on Lubrication.509 

Advice to Buyers of Second-Hand 

Machines .539 

Air Cooled Motors, Efficiency of.110 

Air Cooling Flanges.Ill 

Air or Water Cooling.109 

Air Pressure for Tires.539 

Air Propeller for Propulsion.337 

Air Resistance, Effect on Power 

Needed . 59 

Alarms for Motorcycles.499 

Alinement of Side Cars.432 

American Motorcycles, Pioneer 

Forms . 32 

Anti-Friction Bearings, Installa¬ 
tion of.211 

Attachment of Side Car.431 

Automatic and Mechanical 

Valves .168 : 

Automatic Carburetors .240 , 

Automatic Hand Pump.221 

Automobile Practice, Influence 

of . 68 

Auto-Varia Pulley.307 i 


Page 

Battery Ignition for Two-Cylin¬ 


der Engine.264 

Battery Timer Construction.266 

Bearings, Plain and Anti-friction 205 

Belt Connectors.344 

Belt Construction .344, 348 

Belt Drive, Advantages of.340 

Belt Drive, Flat.341 

Belt Drive, In Combination with 

Chain .358 

Belt Drive, Slipping.526 

Belt Drive Systems.339 

Belt Idler, Utility of.342 

Belt Pulley Lagging.349 

Belts, Connectors for.344 

Belts, Tool for Repairing.345 

Bevel and Worm Gear Drive... .364 

Bore and Stroke Ratio.164 

Bowden Wire Control.446 

Bowden Wire, How Used.448 

Bowden Wire Installation.450 

Brake Action, Principle of.411 

Brake, Force Required at.409 

Brake, Multiple-disc.417 

Brake, Operation of Typical.420 

Brake, What It Should Do.407 

Brakes, Adjustment of.532 

Brakes, External.415 

Brakes, Internal.416 

Brakes, Why Necessary.404 

Breeze Carburetors.244 

Built-up Crankshafts.200 


Calculating Length of Chain... .360 

Ball Bearings, How to Install.. .214 Calculating Sprocket Sizes.362 

Battery Ignition for One Cylin- j Carbon Deposits, Removing.521 

der .264 Carburetion Group Troubles.516 

542 































































Index 


543 


Page 


Carburetion, Principles Outlined 234 

Carburetor, Definition of.235 

Carburetor, Hedstrom.240 

Carburetors, Automatic .240 

Carburetors, Breeze .244 

Carburetors, Early Forms...,.. .235 
Carburetors, Elements of Design 239 
Carburetors, English .247 


Carburetors, Float Feed.23S 

Carburetors, Kingston .243 

Carburetors, Longuemare .241 

Carburetors, Schebler .242 

Care of Leather Belts.527 

Carrying Cases, Forms of.503 

Causes of Lost Compression.517 

Causes of Noisy Operation.519 

Change Speed Gear, Unit Type. .312 
Change Speed Gearing, Derange¬ 
ments .531 

Change Speed Gearing, Why De¬ 
sirable .299 

Change Speed Gears, Location of 304 

Chain Alinement, Testing.525 

Chain Drive, Advantages of.350 

Chain Drive, Double .354 

Chain Drive, Eagle .354 

Chain Drive, In Combination 

with Belt.358 

Chain Drive, Indian.355 

Chain Drive, Single .354 

Chain Drive Systems, Design of.353 

Chains, How to Adjust.525 

Classification of Motorcycle Types 41 

Clutch, Advantages of.286 

Clutch, Cone .296 

Clutch Defects.528 

(dutch, Eclipse Countershaft... .294 
Clutch, Eclipse Engine Shaft....293 

Clutch, Engine Shaft.293 

Clutch Location.292 

Clutch, Multiple Disc.290 

Clutch, Theory of Action.287 

Clutch, Utility Defined.285 


Page 


Clutches, Materials Employed in 291 

Clutches, Types of..288 

Clutches, Typical Motorcycle.... 292 

Coaster Brake, Operation of.420 

Combination Chain and Belt 

Drive .358 

Combustion Chamber Design.... 153 

Combustion, Character of.91 

Commercial Motorcycle. 53 

Compression, Influence on Tower 165 

Compression, Value of.91 

Concentric Rings.194 

Conditions Determining Chain 

Drive Design.353 

Cone Clutch, Reading-Standard. .296 
Connecting Rods, For Twin Mo¬ 
tors .197 

Connecting Rods, Premier.198 

Connecting Rods, Simple.197 

Connectors for Driving Belts.... 344 
Construction of Engine Base... .203 

Control of Motor Speed.504 

Conventional Valve Placing.159 

Cooling Engine, Air or Water...109 

Cooling Engine, Reason for.107 

Countershaft Gear.311 

Countershaft Gear, Planetary.. .330 
Countershaft Gear, Shifting Jaw 

Clutch .316 

Countershaft Gear, Sliding Gear.320 
Countershaft Gear, Three Speed.321 
Cradle Dynamometer, How Used.100 

Cradle Spring Forks.388 

Cradle Spring Frame.397 

Crankshaft for Four Cylinder.. .201 


Crankshaft Forms and Flywheelsl99 


Crankshafts, Built Up.200 

Crank Starter, Henderson.433 

Current Production Methods.... 260 
Cutting Out Magneto Ignition.. .279 

Cyclecar, Definition of.455 

Cyclecar Features.452 



























































544 


Index 


Page 

Cyclecars, Advantage of Narrow 

Tread .467 

Cyclecars, Change Speed Devices 

for .481 

Cyclecars, Chassis Design of....469 
Cyclecars, Control Methods of.. .49.3 
Cyclecars, Friction Drive for.... 481 
Cyclecars, Method of Springing.490 
Cyclecars, Planetary Gear for...483 

Cyclecars, Power Plants for.470 

Cyclecars, Power Transmission 

Methods .484 

Cyclecars, Seating Arrangement 

in .466 

Cyclecars, Steering Arrange¬ 
ments of.4S9 

Cyclecars, Three-wheel .458 

Cyclecars, Typical Forms.461 

Cylinder Oil, Properties of.218 

Cylinders, Combustion Chambers 

of .153 

Cylinders, Detachable Head 

Types .146 

Cylinders, Material Employed 

for .152 

Cylinders, Method of Construc¬ 
tion .145 

Cylinders, Method of Finishing.. 152 
Cylinders, One Piece.146 


Daimler Motorcycle. 20 

Daimler Motorcycle with Coun¬ 
tershaft Drive. 22 

Daimler’s First Twin Engine.... 21 

Daimler, Work of. 20 

De Dion Motorcycle, First. 25 

Defects in Clutches.528 

Definition of Torque.102 

De Luxe Motor, Instructions for 

Running .522 

Demand for More Power. 38 

Derangements in Change Speed 
Gearing .,.531 


Page 

Design of Chain Drive Systems.353 
Detachable Cylinder Heads, Ad¬ 


vantages of.14S 

Detection of Magneto Faults... .281 

Determining Power Needed. 55 

Devices for Supplying Oil.218 

Diagrams of Horsepower Tests. .105 

Double Chain Drive.354 

Driving Belt Sizes.350 

Driving Belt, Wata-Wata .341 

Driving Belt, Whittle .344 

Driving Belts, Flat.342 

Driving Belts, Flexible V-forms.344 

Driving Belts, Leather.344 

Driving Belts, Round.343 

Driving Belts, Rubber.344 

Driving Belts, Standard Types..346 

Driving Belts, Types of.343 

Driving Chains, Types of.355 

Dry Battery for Ignition.260 


Early History of Indian Motor¬ 
cycle . 30 

Early Vaporizer Forms.235 

Eccentric Rings.194 

Eclipse Countershaft Clutch.294 

Eclipse Engine Shaft Clutch... .293 
Efficiency of Air Cooled Motors.. 110 
Efficiency of Power Transmis¬ 
sion .33S 

Electrical Ignition, Elements of.258 

Electrical Ignition Systems.25S 

Electric Starting, Diagram for..439 
Electric Starting System, Indian.437 
Elements of Electrical Ignition. .258 

Enclosed Gear Drive.366 

Engine Base Construction.203 

Engine Defects .512 

Engine Efficiency, Effect of Valve 

Placing .155 

Engine Shaft Gear.310 

Equipment for Motorcycles.495 

























































Index 


545 


Page 

Equipment, How Harried.503 

Equipment, Spare Parts.502 

Equipment, Tool Outfits.501 

Excelsior Planetary Gear Set....331 

Exhaust Valve Design.171 

Exhaust Valve Lift.184 

Exhaust Valve Timing.190 

Explosion Pressures for Various 
Compressions .105 

Factors in Brake Design.414 

Features of Two-Cycle Engines.. 96 
Features of Main Engine Types. 85 

Figuring Grade Percentage. 65 

Flanges, Construction of Air 

Cooling .Ill 

Flat Belt Drive.342 

Flywheel Design.202 

Foot Boards, Types of.381 

Foot Boards, Value of.381 

Foot Best Construction.381 

Force Required at Brake.409 

Foreign Motorcycle Designs. 83 

Foreign Spring Forks.391 

Forks with Trailing Hubs.388 

Forms of Lubricants .217 

Forms of Plunger Pump.220 

Forms of Wristpin .196 

Formulae, for Determining Horse¬ 
power . 97 

Four-Cycle Engine, Operation of. 87 

F<>ur-CyUnder Crankshaft.201 

Four-Cylinder Motorcycle En¬ 
gines .130 

Frame Construction .372 

Frame Construction, Loop.373 

Framfe Construction, Open.373 

Frames, Method of Construction.379 

Frames, Spring .396 

Fuel Filters or Strainers.248 

Functions of Engine Parts.141 


Page 

Gasoline, Air Needed to Burn...234 
Gasoline, Chemical Composition 

of .234 

Gasoline Engine and Auxiliary 

Devices . 84 

Gear Ratio, Relation to Engine 

Power .368 

Gear Ratio, Tables of.370 

Grade Percentage, Method of 

Figuring . 65 

Gradients, Effects of. 61 

Gradients, Table of. 64 


Hand Lever Control.445 

Heavy Weight Motorcycles. 51 

Hedstrom Automatic Carburetor .241 
High Tension Magneto Action...267 

Horizontal A'alves.157 

Horsepower, Brake Tests of.101 

Horsepower, Diagrams .105 

Horsepower Formulae. 97 

Horsepower, How Tested.100 

Horsepower, Methods of Figur¬ 
ing . 97 

Horsepower, Table of. 99 

Horsepower Tests with Dyna¬ 
mometer .100 

How Compressed Gas is Ignited.257 

How Fuel is Carried.233 

How Horsepower is Tested.100 

How Motorcycle Developed from 

Bicycle . 19 

How Rider’s Effort is Multiplied.423 

How to Adjust Chains.525 

How Valves are Operated.176 

Hub Type Clutch.297 


Ignition System Faults, Testing.515 
Indian Motorcycle, Early His¬ 


tory of. 30 

Indian Motorcycle Frame.372 
























































54fi 


Index 


Page 


Indian Multiple Disc Clutch.-05 

Indian Two-Speed Gear.310 

Inflation Table.530 

Influence of Roads on Traction 

Resistance . 56 

Inlet Manifold Design.250 

Inlet Valve Design.173 

Inlet Valve Timing.190 

Inner Tube Forms.427 

Inner Tubes, Repairing.533 

Instructions for De Luxe Motors.522 
Instructions for Operating Motor¬ 
cycles .505 

Instructions for Starting Motor. .503 
Irregular Motor Operation, 
Causes of.517 


Kick Starter, Indian.433 

Kingston Carburetors.243 

Laminated Leaf Spring Forks.. .388 

Leather Belts, Care of.527 

Length of Chain Needed, Rules 

for .360 

Levers for Bowden Wire.448 

Lifting Exhaust Valves.1S4 

Lighting Systems, Electric.498 

Lighting Systems, Gas.497 

Light vs. Medium Weight Con¬ 
struction . 47 

Light Weight Motorcycles. 45 

Loads on Plain Bearings.208 

Location of Change Speed Gears.304 

Location of Clutch.292 

Longuemare Carburetors.246 

Lost Compression, Causes of... .517 

Lubricants, Forms of.217 

Lubricating Systems, Constant 

Level Splash .226 

Lubricating Systems, Indian... .224 
Lubricating Systems, Mechan¬ 
ical .223 


Page 

Lubricating Systems, Pressure...228 
Lubricating Systems, Royal En¬ 


field .225 

Lubricating Two-Cycle Engine...229 

Lubrication, Advice on.509 

Lubrication, Theory of.215 


Magneto Contact Breaker Con¬ 
struction .270 

Magneto Cut-out Switch.279 

Magneto Driving Means.273 

Magneto Faults, Detection of.. .281 
Magneto, For Four-Cylinder En¬ 
gines .271 


Magneto Ignition, Merits of.268 

Magneto, Operation of.272 

Magneto, Parts of High Tension.269 

Magneto Timing.274 

Main Engine Types, Features of. 85 

Manifolds, Design of Inlet.250 

Materials for Clutches.291 

Mechanical Lubricating Systems.223 
Mechanical Oil Pump, Indian...224 
Mechanical Valves, Advantages 

of . 171 

Medium Weight Motorcycles. 47 

Methods of Cylinder Construc¬ 
tion .145 

Methods of Figuring Horsepower 97 
Methods of Power Transmission.333 

Motorcycle, Advantages of. 17 

Motorcycle Alarms.499 

Motorcycle, Commercial. 53 

Motorcycle Control Methods.443 

Motorcycle, I minder's Earl y 

Form . 20 

Motorcycle Design, Influence of 

Automobile Practice. 68 

Motorcycle Engine Parts.141 

Motorcycle Engines, W a t e r 

Cooled .113 

Motorcycle Equipment .495 
























































Index 


547 


Page 

Motorcycle Frame, Cradle Spring397 

Motorcycle Frame, Schickel.376 

Motorcycle Frame Tubing, Rein¬ 
forced .379 

Motorcycle Frame Tubing, Size 

of . 3S0 

Motorcycle Fuel, Derivation and 

Use .230 

Motorcycle Fuel, How Carried..233 
Motorcycle, How Developed from 

Bicycle . 19 

Motorcycle, Parts and Functions 70 


Motorcycle, 

Pioneer 

Forms. 

. 20 

Motorcycle 

Power 

Plants, 

Four- 

Cycle Principles. 


.87 

Motorcycle 

Power 

Plants, 

Four 

Cylinder 



.130 

Motorcycle 

Power 

Plants, 

Hen- 

derson .. 



.132 

Motorcycle 

Power 

Plants, 

One 

Cylinder 



.IIS 

Motorcycle 

Power 

Plants, 

Scott 

Two-Cycle . 


.127 

Motorcycle 

Power 

Plants, 

Two- 

Cylinder 



.122 


Motorcycle Saddles .400 

Motorcycle, Stock Racer. 53 

Motorcycle Tires .424 

Motorcycle Tool Outfit.501 

Motorcycle Troubles, Classifica¬ 
tion of.512 

Motorcycle, Wolfmueller . 23 | 

Motorcycle, Why Popular. IS j 

Motorcycles, Distinctive New Era 

Design . 36 J 

Motorcycles, Essential Require¬ 
ments of. 40 

Motorcycles, Foreign Design. 79 

Motorcycles, General Character¬ 
istics . 74 

Motorcycles, Heavy Weight. 51 

Motorcycles, Light Weight. 45 

Motorcycles, Medium Weight.... 47 


Page 


Motorcycles, Method of Starting.432 

Motorcycles, Power Needed. 55 

Motorcycles, Power Plant Group. 84 
Motorcycles, Some Modern De¬ 
signs . 76 

Motorcycles, Steam Power for... 42 
Motorcycles, Type Classification. 41 

Motor-quadricycles . 26 

Motor Speed Control....504 

Muffler Cut-out, Utility of.255 

Mufflers, Design of.253 

Mufflers, How They Operate... .252 

Mufflers, Typical Forms.254 

Multiple Cylinder Motors, Ad¬ 
vantages of.120 

Multiple Disc Clutch.290 

Multiple Disc Clutch, Hub Type.297 
Multiple Disc Clutch, Indian... .295 


New Era Design.36 

Noisy Operation, Some Causes 
of . 519 

Offset Cylinders, Advantages of. .166 

Oil, Devices for Supplying.218 

Oil Supply with Gasoline.230 

One-Cylinder Motors, Features 

of .118 

Operating Motorcycles, Instruc¬ 
tions for .505 

Outer Casing Construction.426 

Outer Casing Repairs.535 

Overheating, Conditions Produc¬ 
ing .518 

Parts and Functions of Motor¬ 
cycles . 70 

Pearson & Cox Steam Motorcycle 42 
Pioneer Forms of American Mo¬ 
torcycles . 32 

















































548 


Index 


Page 


Pioneer Motorcycles. 2o 

Pistons anti Piston Rings.194 

Piston Speed, Meaning of.164 


Plain and Anti-friction Engine 


Bearings .205 

Plain Bearings, Loads on.208 

Planetary Countershaft Gear....330 

Plunger Pump, Automatic.221 

Plunger Pump Forms.220 

Power in Proportion to Weight.. 66 
Power Needed, Effect of Air Re¬ 
sistance . 59 

Power Needed, Effect of Gradi¬ 
ents . 61 

Power Needed, Effect of Speed 

on . 57 

Power Plant Group of Motor¬ 
cycles . S4 

Power Plant Support and Loca¬ 
tion . 134 

Power Plant, Two-Cycle .93 

Power Plant, Two C y 1 i n d e r 

Form . 92 

Power Plants, Four-Cycle. 87 

Power Transmission by Belt 

Drive .339 

Power Transmission by Bevel 

Gear .364 

Power Transmission by Worm 

Gear .366 

Power Transmission, Defects in.529 
Power Transmission, Flat Belt 

for .342 

Power Transmission Methods....333 
Power Transmission Methods, 

Unconventional .337 

Power Transmission Parts.285 

Principle of Brake Action.411 

Principle of Four-Cycle Engine.. 87 
Principle of Two-Cycle Engine.. 93 

Pulley, Auto-Va ria.306 

Pulleys, Variable Speed.305 

rump Circulation System.114 


Page 

Radiators for Water Cooling.... 114 

Radiators, Installation of.116 

Rear Hub Gear, Harley-David- 

son .324 

Rear Hub Gear, Sturmey-Archer.326 

Rear Hub Gear, Thiem.323 

Rear Hub Three-Speed Gear.325 

Rear Hub Two-Speed Gear.322 

Rear Wheel Stands.383 

Rear Wheel Stands, Eagle Auto¬ 
matic .385 

Reason for Cooling Engine.107 

Regulating Motorcycle Speed... .507 
Relation of Engine Power to 

Gear Ratio.368 

Removing Carbon Deposits.521 

Repairing Inner Tubes.533 

Repairs to Outer Casings.535 

Requirements of Motorcycles.... 40 

Rims and Tire Sizes.538 

Rim Table.538 

Roller Chain Parts.357 

Rudge-Whitworth Variable Pul¬ 
ley .309 


Saddles, Motorcycle.400 

Schebler Carburetors.242 

Scott Two-Cycle Engine.127 

Seat Posts, Spring.395 

Second-Hand Machines, Advice 

to Buyers of.539 

Side Car Advantages .427 

Side Car Alinement .432 

Side Car Attachment .431 

Side Car, Castor Wheel .429 

Side Car, Flexible .430 

Side Car Forms.428 

Side Car, Rigid Wheel.428 

Side Cars, Chassis of.431 

Sight Drip Feeds.219 

Simple Battery Ignition Sys¬ 
tems .262 






























































Index 


Page 

Simple Splash System.219 

Single Chain Drive.354 

“Skipping,” Cause of.517 

Sliding Gear Type.332 

Slipping Belt Drive.526 

Slipping Clutch, Effect of.301 

Slipping Clutch, Power Loss in. .301 

Spare Parts for Equipment.502 

Spark Lever, Rules for Use of..507 

Spark Plug, Location.267 

Spark Plugs, Construction of....267 
Speed Equivalents, American 

and French .370 

Speed Formula.370 

Speed, How it Affects Power 

Needed . 57 

Speed Over Measured Mile.371 

Spring Forks, Eagle .388 

Spring Forks, Foreign .391 

Spring Forks, Reading-Standard.388 

Spring Forks, Types of.387 

Spring Forks, Value of.386 

Spring Forks, Yale .387 

Spring Frames .396 

Spring Seat Posts .395 

Spring Seat Post, Eagle.395 

Spring Seat Post, Reading-Stand¬ 
ard .395 

Spring Seat Post, Yale.395 

Sprocket Sizes, Calculating.362 

Standard Driving Belts.346 

Stands, Rear Wheel.383 

Starting Motorcycle Engines-432 

Starting Motor, Directions for...503 

Steering Head Construction.378 

Step Starter, llarley-Davidson.. .435 

Stock Racer, Motorcycle. 53 

Storage Battery for Ignition... .261 

Strainers for Fuel.248 

Support of Power Plants.134 


549 

Page 


Tandem Attachments.403 

Testing Chain Alinement.525 

Testing Horsepower.100 

Testing Ignition System.515 

Theory of Friction Clutch Ac¬ 
tion .287 

Thermo Syphon Cooling.114 

Three-Port Two-Cycle Engine... 94 
Three-Speed Gear, Rear Hub... .326 
Timing High Tension Magnets... 274 

Timing Overhead Valves.193 

Timing Valves .190 

Tire Inflation Table.539 

Tires for Motorcycles.424 

Tools for Belt Repairs.345 

Tools for Motorcycles .501 

Torque, Definition of.102 

Torque, Relation to Horsepower.102 
Traction Resistance, Influence of 

Roads on. 56 

Troubles with Automatic Valves. 170 
Twisting Grip Control.444 


Two-Cycle Engine, Three-Port... 94 
Two-Cycle Engine, Two-Port.... 93 
Two-Cycle Engines, Lubricating.229 
Two-Cycle Motor, Features of... 96 
Two Cylinder Motors, Types of..122 


Two-Port Two-Cycle Engine. 93 

Two Speed Gear, Excelsior.330 

Two Speed Gear, Indian .316 

Two Speed Gear, Rear Hub 

Type .322 

Types of Clutches.288 

Types of Driving Chains.355 

Types of Spring Forks.387 

Types of Two Cylinder Motors. .122 

Typical Motorcycle Clutches.292 

Typical Motorcycle Motors, 
Water Cooled.116 


Use and Abuse of Muffler Cut¬ 
out 


Table of Horsepower 


99 


255 


























































550 


Index 


Page 


Utility of Clutch Defined.285 

Utility of Hand Pump.210 


Value of Variable Speed Gears. .300 
Valve Design and Construction.. 171 

Valve Grinding . 519 

Valve Operating Mechanism, In¬ 
dian .1S3 

Valve Operating Mechanisms, 

Precision .185 

Valve Placing, Conventional ....159 

Valve Placing, Horizontal .157 

Valve Placing, In Cylinder Head.156 


Valve Placing in L Cylinder.... 161 

Valve Placing in T Cylinder_161 

Valve Placing, Relation to En¬ 
gine Efficiency.155 

Valve Removal .519 

Valve Timing, How Gears are 


Marked . 

.187 

Valve Timing, Typical... 

.187 

Valves, Automatic . 

.168 

Valves, Construction of.. 

.174 

Valves, Holding Spring 

Collar 

of . 


Valves, How Operated... 

.176 

Valves, How Operated when in 

Head . 


Valves, Mechanical. 

.168 

Vaporizers, Defects of 

Simple 

Forms . 

.238 


Vaporizers, Early Forms of.235 

Vaporizers, Float Feed Type. .. .238 
Vaporizers, Mixing Valve Type..236 


Page 

Vaporizers, Surface Type.235 

Vaporizers, Wick Feed.237 

Variable Pulley, Rudge-Whit¬ 
worth .309 

Variable Speed by Slipping 

Clutch .301 

Variable Speed Gears, Counter¬ 
shaft .311 

Variable Speed Gears, Value of.300 
Variable Speed Gear, Engine 

Shaft .310 

Variable Speed Gear, Plielon & 

Moore .327 

Variable Speed Gear, Royal En¬ 
field .32S 

Variable Speed Gear, Sliding 

Gear Type.332 

Variable Speed Gear, Three 

Chain . ....326 

Variable Speed Pulley, Auto- 

Varia .307 

Variable Speed Pulleys.305 


Wall Auto-Wheel ..338 

Water Cooled Motors, Typical... 116 

Water Cooling Methods.113 

Water Cooling, Pump Circula¬ 
tion .H4 

Water Cooling, Radiators for... 114 
Water Cooling, Thermo-Syphon.. 114 
Why Motorcycles are Popular... 18 

Wolfmueller Motorcycle. 23 

Work of Daimler. 20 

Wrist Pin, Use of.196 










































PRACTICAL SCIENTIFIC 

TECHNICAL 


EACH BOOK IN THIS CATALOGUE IS WRITTEN BY 
AN EXPERT AND IS WRITTEN SO YOU 
CAN UNDERSTAND IT 


THE NORMAN W. HENLEY PUBLISHING COMPANY 

Publishers of Scientific and Practical Books 
132 Nassau Street New York, U.S. A. 


^TOKHOlUe^ 


% 


Any book in this Catalogue sent prepaid on receipt of price. 































SUBJECT INDEX 


{ 


Accidents. 18 

Air Brakes.17, 19 

Arithmetics. 20 

Automobiles. 3 

Balloons. 3 

Bevel Gears. 14 

Boilers. 22 

Brazing. 3 

Cams. 15 

Car Charts. 4 

Change Gear. 14 

Charts.3, 4, 22 

Chemistry. 23 

Coal Mining. 23 

Coke. 4 

Compressed Air. 5 

Concrete. 5 

Cyclopedia.4, 20 

Dictionaries. 7 

Dies... 7 

Drawing.8, 24 

Drop Forging. 7 

Dynamo.9, 10, 11 

Electricity.9, 10, 11, 12 

Engines and Boilers. 22 

Factory Management. 12 

Flying Machines. 3 

Fuel. 13 

Gas Manufacturing. 14 

Gas Engines.13, 14 

Gears. 14 

Heating, Electric. 9 

Hot Water Heating. 27 

Horse-Power Chart. 4 

Hydraulics. 15 

Ice Making. 15 

India Rubber. 25 

Interchangeable Manufacturing. 20 

Inventions. 15 

Knots. 15 

Lathe Work. 16 

Lighting (Electric). 9 

Link Motion. 17 

Liquid Air. 16 

Locomotive Boilers. 18 

Locomotive Engineering.17, 18, 19 

Machinist’s Books.20, 21, 22 


PAGE 

Manual Training. 22 

Marine Engines.. 22 

Marine Steam Turbines. 29 

Mechanical Movements.... . .20, 21 

Metal Turning. 16 

Milling Machines. 21 

Mining.22, 23 

Oil Engines. 13 

Patents. 15 

Pattern Making. 23 

Perfumery. 23 

Pipes. 28 

Plumbing . 24 

Producer Gas. 13 

Punches. 7 

Railroad Accidents. 18 

Receipt Book.23, 25 

Refrigeration. 15 

Rope Work. 15 

Rubber Stamps.'. 25 

Saws. 26 

Sheet Metal Working. 7 

Shop Tools. 21 

Shop Construction. 20 

Shop Management. 20 

Sketching Paper. 8 

Smoke Prevention. 13 

Soldering. 3 

Splices. 15 

Steam Engineering.26, 27 

Steam Heating. 27 

Steam Pipes. 28 

Steel. 28 

Superheated Steam. 17 

Switchboards.9, 11 

Tapers. 16 

Telephone. 12 

Threads. 22 

Tools. 20, 22 

Turbines. 29 

Ventilation. 27 

Valve Gear. 19 

Valve Setting. 17 

Walschaert Valve Gear. 19 

Watchmaking. 29 

Wiring.9, 11, 12 


Wireless Telephones and Telegraphy,... 12 


%ar any of these books promptly sent prepaid to any address in 

THE WORLD ON RECEIPT OF PRICE. 

to Remit .—«By Postal Money Order, Express Money Order, Bank Draft 

or Registered Letter. 

% 







































































































CATALOGUE OF GOOD, PRACTICAL BOOKS 


AUTOMOBILE 


THE MODERN GASOLINE AUTOMOBILE—ITS DESIGN, CONSTRUCTION, 
MAINTENANCE AND REPAIR. By Victor W. Page, M. E. 

The latest and most complete treatise on the Gasoline Automobile ever issued. Written 
in simple language by a recognized authority, familiar with every branch of the automobile 
industry. Free from technical terms. Everything is explained so simply that anyone of 
average intelligence may gain a comprehensive knowledge of the gasoline automobile. 
The information is up-to-date and includes, in addition to an exposition of principles of 
construction and description of all types of automobiles and their components, valuable 
money-saving hints on the care and operation of motor cars propelled by internal combus¬ 
tion engines. Among some of the subjects treated might be mentioned: Torpedo and other 
symmetrical body forms designed to reduce air resistance; sleeve valve, rotary valve and 
other types of silent motors; increasing tendency to favor worm-gear power-transmission; 
universal application of magneto ignition; development of automobile electric-lighting 
systerns; block motors; underslung chassis; application of practical self-starters; long stroke 
and offset cylinder motors; latest automatic lubrication systems; silent chains for valve 
operation and change-speed gearing; the use of front wheel brakes and many other detail 
refinements. 

By a careful study of the pages of this book one can gain practical knowledge of automobile 
construction that will save time, money and worry. The book tells you just what to do, how 
and when to do it. Nothing has been omitted, no detail has been slighted. Every part of 
the automobile, its equipment, accessories, tools, supplies, spare parts necessary, etc., have 
been discussed comprehensively. If you are or intend to become a motorist, or are in 
any way interested in the modern Gasoline Automobile, this is a book you cannot afford to 
be without. Nearly 600 6x9 pages—and more than 500 new and specially made detail il¬ 
lustrations. as well as many full page and double page plates, showing all parts of the 
automobile. Including nine large folding plates. Price. $2.50 

BALLOONS AND FLYING MACHINES 


MODEL BALLOONS AND FLYING MACHINES. WITH A SHORT ACCOUNT OF 
THE PROGRESS OF AVIATION. By J. H. Alexander. 

This book has been written with a view to assist those who desire to construct a model airship 
or flying machine. It contains five folding plates of working drawings, each sheet containing 
a different sized machine. Much instruction and amusement can be obtained from the making 
and flying of these models. 

A short account of the progress of aviation is included, which will render the book of greater 
interest. Several illustrations of full sized airship and flying machines of the latest types are 
scattered throughout the text. This practical work gives data, working drawings, and details 
which will assist materially those interested in the problems of flight. 127 pages, 45 illustra¬ 
tions, 5 folding plates. Price..$1.50 

BRAZING AND SOLDERING 


BRAZING AND SOLDERING. By James F. Hobart. 

The only book that shows you just how to handle any job of brazing or soldering that comes 
nlong; tells you what mixture to use, how to make a furnace if you need one. Full of 
valuable kinks. The fifth edition of this book has just been published, and to it much 
new matter and a large number of tested formulas for all kinds of solders and fluxes have 
been added. Illustrated.25 cents 


CHARTS 


MODERN SUBMARINE CHART—WITH 200 PARTS NUMBERED AND NAMED. 

A cross-section view, showing clearly and distinctly all the interior of a Submarine of the 
latest type. You get more information from this chart, about the construction and opera¬ 
tion of a Submarine, than in any other way. No details omitted—everything is accurate 
and to scale. It is absolutely correct in every detail, having been approved by Naval 
Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown, and 
to make the engraving more readily understood all the features are shown in operative form, 
with Officers and Men in the act of performing the duties assigned to them in service con¬ 
ditions. This CHART IS REALLY AN ENCYCLOPEDIA OF A SUBMARINE. It 
ig educational and worth many times its cost. Mailed in a Tube for....25 cent® 


3 



















CATALOGUE OF GOOD, PRACTICAL BOOKS 


BOX CAR CHART. 

A chart showing the anatomy of a box car, having every part of the car numbered and its 
proper name given in a reference list.. 20 cents 

GONDOLA CAR CHART. 

A chart showing the anatomy of a gondola car, having every part of the car numbered and 
its proper reference name given in a reference list. 20 cents 

PASSENGER CAR CHART. 

A chart showing the anatomy of a passenger car, having every part of the car numbered and 
its proper name given in a reference list. 20 cents 

WESTINGHOUSE AIR-BRAKE CHARTS. 

Chart I.—Shows (in colors) the most modern Westinghouse High Speed and Signal Equip¬ 
ment used on Passenger Engines, Passenger Engine Tenders, and Passenger Cars. Chart 
II.—Shows (in colors) the Standard Westinghouse Equipment for Freight and Switch En¬ 
gines, Freight and Switch Engine Tenders, and Freight Cars. Price for the set . 50 cent* 

TRACTIVE POWER CHART. 

A chart whereby you can find the tractive power or drawbar pull of any locomotive, without 
making a figure. " Shows what cylinders are equal, how driving wheels and steam pressure 
affect the power. What sized engine you need to exert a given drawbar pull or anything 
you desire in this line. 50 cents 

HORSE POWER CHART. 

Shows the horse power of any stationary engine without calculation. No matter what the 
cylinder diameter of stroke; the steam pressure or cut-off; the revolutions, or whether con¬ 
densing or non-condensing, it’s all there. Easy to use, accurate, and saves time and calcu¬ 
lations. Especially useful to engineers and designers. 50 cents 

BOILER ROOM CHART. By Geo. L. Fowler. 

A Chart—size 14 x 28 inches—showing in isometric perspective the mechanisms belonging 
in a modern boiler room. Water tube boilers, ordinary grates and mechanical stokers, feed 
water heaters and pumps comprise the equipment. The various parts are shown broken or 
removed, so that the internal construction is fully illustrated. Each part is given a reference 
number, and these, with the corresponding name, are given in a glossary printed at the sides. 
This chart is really a dictionary of the boiler room—the names of more than 200 parts being 
given. It is educational—worth many times its cost. 25 cents 

CIVIL ENGINEERING 


HENLEY’S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED 
TRADES. Edited by Joseph G. Horner, A. M. I. E. M. 

This set of five volumes contains about 2,500 pages with thousands of illustrations, including 
diagrammatic and sectional drawings with full explanatory details. This work covers the 
entire practice of Civil and Mechanical Engineering. The best known experts in all branches 
of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted 
to the needs of the beginner and the self-taught practical man, as well as the mechanical en¬ 
gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be 
found a means of advancement to any progressive man. It is encyclopedic in scope, thorough 
and practical in its treatment of technical subjects, simple and clear in its descriptive matter, 
and without unnecessary technicalities or formulae. The articles are as brief as may be and 
yet give a reasonably clear and explicit statement of the subject, and are written by men who 
have had ample practical experience in the matters of which they write. It tells you all you 
want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot 
help but understand. As a work of reference it is without a peer. $6.00 per single volume. 
For complete set of five volumes, price . $25.00 


COKE 


COKE—MODERN COKING PRACTICE; INCLUDING THE ANALYSIS OF 
MATERIALS AND PRODUCTS. By T. H, Byrom and J. E. Christopher. 

A handbook for those engaged in Coke manufacture and the recovery of By-products. Fully 
illustrated with folding plates. . It has been the aim of the authors, in preparing this book, 
to produce ore which shall be of use and benefit to those who are associated with, or inter¬ 
ested in, the modern developments of the industry. Contents: I. Introductory. II. Gen- 


4 
















CATALOGUE OF GOOD, PRACTICAL BOOKS 


eral Classification of Fuels. III. Coal Washing. IV. The Sampling and Valuation of Coal, 
Coke, etc. V. The Calorific Power of Coal and Coke. VI. Coke Ovens. VII. Coke Ovens, 
continued. VIII. Coke Ovens, continued. IX. Charging and Discharging of Coke Ovens, 
X. Cooling and Cpndensing Plant. XI. Gas Exhausters. XII. Composition and Analysis 
of Ammoniacal Liquor. XIII. Working-up of Ammoniacal Liquor. XIV. Treatment of 
Waste Gases from Sulphate Plants. XV. Valuation of Ammonium Sulphate. XVI. Direct 
Recovery of Ammonia from Coke Oven Gases. XVII. Surplus Gas from Coke Oven. Use¬ 
ful Tables. Very fully illustrated. Price . . .. $3.50 net 

COMPRESSED AIR 


COMPRESSED AIR IN ALL ITS APPLICATIONS. By Gardner D. Hiscox. 

This is the most complete book on the subject of Air that has ever been issued, and its thirty- 
five chapters include about every phase of the subject one can think of. It may be called an 
encyclopedia of compressed air. It is written by an expert, who, in its 665 pages, has dealt 
with the subject in a comprehensive manner, no phase of it being omitted. Includes the 
physical properties of air from a vacuum to its highest pressure, its thermodynamics, com¬ 
pression, transmission and uses as a motive power; in the Operation of Stationary and Port¬ 
able Machinery, in Mining. Air Tools, Air Lifts, Pumping of Water, Acids, and Oils; the 
Air Blast for Cleaning and Painting, the Sand Blast and its Work, and the Numerous Appli¬ 
ances in which Compressed Air is a Most Convenient and Economical Transmitter of Power 
for Mechanical Work, Railway Propulsion, Refrigeration, and the Various Uses to which 
Compressed Air has been applied. Includes forty-four tables of the physical properties of 
air, its compression, expansion, and volumes required for various kinds of work, and a list of 
patents on compressed air from 1875 to date. Over 500 illustrations, 5th Edition, revised and 
enlarged. Cloth bound, $5.00. Half Morocco, price. $6.50 

CONCRETE > 


ORNAMENTAL CONCRETE WITHOUT MOLDS. By A. A. Houghton. 

The process for making ornamental concrete without molds has long been held as a secret, and 
now, for the first time, this process is given to the public. The book reveals the secret and is 
the only book published which explains a simple, practical method whereby the concrete worker 
is enabled, by employing wood and metal templates of different designs, to mold or model in 
concrete any Cornice, Archivolt, Column, Pedestal, Base Cap, Urn or Pier in a monolithic 
form—right upon the job. These may be molded in units or blocks, and then built up to suit the 
specifications demanded. This work is fully illustrated, with detailed engravings. Price $2.00 

CONCRETE FROM SAND MOLDS. By A. A. Houghton. 

A Practical Work treating on a process which has heretofore been held as a trade secret by 
the few who possessed it, and which will successfully mold every and any class of ornamental 
concrete work. The process of molding concrete with sand molds is of the utmost practical 
value, possessing the manifold advantages of a low cost of molds, the ease and rapidity of 
operation, perfect details to all ornamental designs, density, and increased strength of the 
concrete, perfect curing of the work without attention and the easy removal of the molds re¬ 
gardless of any undercutting the design may have. 192 pages. Fully illustrated. Price $2.00 

CONCRETE WALL FORMS. By A. A. Houghton. 

A new automatic wall clamp is illustrated with working drawings. Other types of wall 


forms, clamps, separators, etc., are also illustrated and explained. 50 cents 

CONCRETE FLOORS AND SIDEWALKS. By A. A. Houghton. 

The molds for molding squares, hexagonal and many other styles of mosaic floor and side¬ 
walk blocks are fully illustrated and explained. 50 cents 


PRACTICAL CONCRETE SILO CONSTRUCTION. By A. A. Houghton. 

Complete working drawings and specifications are given for several styles of concrete silos, 
with illustrations of molds for monolithic and block silos. The tables, data and information 
presented in this book are of the utmost value in planning and constructing all forms of concrete 
.. .... 50 cents 

MOLDING CONCRETE CHIMNEYS, SLATE AND ROOF TILES. By 

A. A. Houghton. 

The manufacture of all types of concrete slate and roof tile is fully treated. Valuable data 
on all forms of reinforced concrete roofs are contained within its pages. The construction of 
concrete chimneys by block and monolithic systems is fully illustrated and described. A 
number of ornamental designs of chimney construction with molds are shown in this valu¬ 
able treatise. .• . .... 50 cent# 


5 


















CATALOGUE OF GOOD, PRACTICAL BOOKS 


MOLDING AND CURING ORNAMENTAL CONCRETE. By A. A. Houghton. 

The proper proportions of cement and aggregates for various finishes, also the methods of 
thoroughly mixing and placing in the molds, are fully treated. An exhaustive treatise on this 
subject that every concrete worker will find of daily use and value .50 cent* 

CONCRETE MONUMENTS, MAUSOLEUMS AND BURIAL VAULTS. By A. A. 

Houghton. 

The molding of concrete monuments to imitate the most expensive cut stone is explained in 
this treatise, with working drawings of easily built molds. Cutting inscriptions and designs 
is also fully treated. • 50 cents 

MOLDING CONCRETE BATH TUBS, AQUARIUMS AND NATATORIUMS. 

By A. A. Houghton. 

Simple molds and instruction are given for molding many styles of concrete bath tubs, 
swimming pools, etc. These molds are easily built and permit rapid and successful 
work. ... 60 cents 

CONCRETE BRIDGES, CULVERTS AND SEWERS. By A. A. Houghton. 

A number of ornamental concrete bridges with illustrations of molds are given. A collapsible 
center or core for bridges, culverts and sewers is fully illustrated with detailed instructions for 
building ... . 60 cents 

CONSTRUCTING CONCRETE PORCHES. By A. A. Houghton. 

A number of designs with working drawings of molds are fully explained so anyone can easily 
construct different styles of ornamental concrete porches without the purchase of expensive 
molds. . .50 cents 

MOLDING CONCRETE FLOWER POTS, BOXES, JARDINIERES, ETC. By 

A. A. Houghton. 

The molds for producing many original designs of flower pots, urns, flower boxes, jardinieres, 
etc., are fully illustrated and explained, so the worker can easily construct and operate 
same.. . .50 cents 

MOLDING CONCRETE FOUNTAINS AND LAWN ORNAMENTS. By 

A. A. Houghton. 

The molding of a number of designs of lawn seats, curbing, hitching posts, pergolas, sun dials 
and other forms of ornamental concrete for the ornamentation of lawns and gardens, is 
fully illustrated and described. 50 cents 

CONCRETE FOR THE FARM AND SHOP. By A. A. Houghton. 

The molding of drain tile, tanks, cisterns, fence posts, stable floors, hog and poultry houses 
and all the purposes for which concrete is an invaluable aid to the farmer are numbered 
among the contents of this handy volume. 50 cents 

POPULAR HANDBOOK FOR CEMENT AND CONCRETE USERS. By Myron 
H. Lewis, 

This is a concise treatise of the principles and methods employed in the manufacture and use 
of cement in all classes of modern works. The author has brought together in this work all 
the salient matter of interest to the user of concrete and its many diversified products. The 
matter is presented in logical and systematic order, clearly written, fully illustrated and free 
from involved mathematics. Everything of value to the concrete user is given including kinds 
of cement employed in construction, concrete architecture, inspection and testing, water¬ 
proofing, coloring and painting, rules, tables, working, and cost data. The book comprises 
thirty-three chapters, as follows: 

Introductory. Kinds of Cements and How They are Made. Properties, Testing and 
Requirements of Hydraulic Cement. Concrete and its Properties. Sand, Broken Stone and 
Gravel for Concrete. How to Proportion the Materials. How to Mix and Place Concrete. 
Forms for Concrete Construction. The Architectural and Artistic Possibilities of Concrete. 
Concrete Residences. Mortars, Plasters and Stucco and How to Use Them. The Artistic 
Treatment of Concrete Surfaces Concrete Building Blocks The Making of Ornamental 
Concrete Concrete Pipes, Fences, Posts, Etc. Essential Features and Advantages of Reen¬ 
forced Concrete. How to Design Reenforced Concrete Beams, Slabs and Columns. Ex¬ 
planations of the Methods and Principles in Designing Reenforced Concrete Beams and 
Slabs, Systems of Reenforcement Employed. Reenforced Concrete in Factory and General 

6 












CATALOGUE OF GOOD, PRACTICAL BOOKS 


Building Construction. Concrete in Foundation Work. Concrete Retaining Walls, Abut¬ 
ments, and Bulkheads. Concrete Arches and Arch Bridges. Concrete Beam and Girder 
Bridges. Concrete in Sewerage and Drainage Works. Concrete Tanks, Dams and Reser- 
voirs. Concrete Sidewalks, Curbs and Pavements. Concrete in Railroad Constructions, 
lhe utility of Concrete on the Farm. The Waterproofing of Concrete Structure. Grout 
or Liquid Concrete and Its Use. Inspection of Concrete Work. Cost of Concrete Work. 
Some of the special features of the book are: 1. The Attention Paid to the Artistic and 
* chitectural Side of Concrete Work. 2. The Authoritative Treatment of the Problem 
of Waterproofing Concrete. 3. An Excellent Summary of the Rules to be Followed in 
Construction. 4. The Valuable Cost Data and Useful Tables given. A valuable 
Addition to the Library of Every Cement and Concrete User. Price.$2.50 

WATERPROOFING CONCRETE. By Myron H. Lewis. 

Modern Methods ofWaterproofing Concrete and Other Structures. A condensed statement 
of the Principles, Rules, and Precautions to be Observed in Waterproofing and Damp¬ 
proofing Structures and Structural Materials. Paper binding. Illustrated. Price. .60 cents 

DICTIONARIES 


STANDARD ELECTRICAL DICTIONARY. By T. O’Conor Sloane. 

An indispensable work to all interested in electrical science. Suitable alike for the student 
and professional. A practical hand-book of reference containing definitions of about 5,000 
distinct words, terms and phrases. The definitions are terse and concise and include every 
term used in electrical science. Recently issued. An entirely new edition. Should be in 
the possession of all who desire to keep abreast with the progress of this branch of science. 
Complete, concise and convenient. 682 pages. 393 illustrations. Price .... $3.00 

DIES—METAL WORK 


DIES: THEIR CONSTRUCTION AND USE FOR THE MODERN WORKING OF 
SHEET METALS. By J. V. Woodworth. 

A most useful book, and one which should be in the hands of all engaged in the press working 
of metals; treating on the Designing, Constructing, and Use of Tools, Fixtures and Devices, 
together with the manner in which they should be used in the Power Press, for the cheap and 
rapid production of the great variety of sheet metal articles now in use. It is designed as a 
guide to the production of sheet metal parts at the minimum of cost with the maximum of 
output. The hardening and tempering of Press tools and the classes of work which may be 
produced to the best advantage by the use of dies in the power press are fully treated. Its 
505 illustrations show dies, press fixtures and sheet metal working devices, the descriptions 
of which are so clear and practical that all metal-working mechanics will be able to understand 
how to design, construct and use them. Many of the dies and press fixtures treated were 
either constructed by the author or under his supervision. Others were built by skilful 
mechanics and are in use in large sheet metal establishments and machine shops. Price $3.00 

PUNCHES, DIES AND TOOLS FOR MANUFACTURING IN PRESSES. By J. V. 

Woodworth. 

This work is a companion volume to the author’s elementary work entitled “Dies, Their 
Construction and Use.’’ It does not go into the details of die making to the extent of the 
author’s previous book, but gives a comprehensive review of the field of operations carried on 
by presses. A large part of the information given has been drawn from the author’s personal 
experience. It might well be termed an Encyclopedia of Die Making, Punch Making, Die 
Sinking, Sheet Metal Working, and Making of Special Tools, Sub-presses, Devices and Mechani¬ 
cal Combinations for Punching, Cutting, Bending, Forming, Piercing, Drawing, Compressing 
and Assembling Sheet Metal Parts, and also Articles of other Materials in Machine Tools. 
2d Edition. Price.$4.00 

DROP FORGING, DIE SINKING AND MACHINE FORMING OF STEEL. By J. V. 

Woodworth. 

This is a practical treatise on Modern Shop Practice, Processes, Methods, Machines, Tools, 
and Details, treating on the Hot and Cold Machine-Forming of Steel and Iron into Finished 
shapes; Together with Tools, Dies, and Machinery involved in the manufacture of Duplicate 

7 










CATALOGUE OF GOOD, PRACTICAL BOOKS 


Forgings and Interchangeable Hot and Cold Pressed Parts from Bar and Sheet Metal. 
This book fills a demand of long standing for information regarding drop forging, die-sinking 
and machine forming of steel and the shop practice involved, as it actually exists in the 
modern drop forging shop. The processes of die-sinking and force-making, which are thor¬ 
oughly described and illustrated in this admirable work, are rarely to be found explained in 
such a clear and concise manner as is here set forth. The process of die-sinking relates to 
the engraving or sinking of the female or lower dies, such as are used for drop forgings, hot 
and cold machine forging, swedging and the press working of metals. The process of force¬ 
making relates to the engraving or raising of the male or upper dies used in producing the 
lower dies for the press-forming and machine-forging of duplicate parts of metal. 

In addition to the arts above mentioned the book contains explicit information regarding 
the drop forging and hardening plants, designs, conditions, equipment, drop hammers, 
forging machines, etc., machine forging, hydraulic forging, autogenous welding and shop 
practice. The book contains eleven chapters, and the information contained in these chapters 
is just what will prove most valuable to the forged metal worker. All operations described 
in the work are thoroughly illustrated by means of perspective half-tones and outline sketches 
of the machinery employed. 300 detailed illustrations. Price. $2.50 


DRAWING—SKETCHING PAPER 


LINEAR PERSPECTIVE SELF-TAUGHT. By Herman T. C. Kraus. 

This work gives the theory and practice of linear perspective, as used in architectural, engh 
peering, and mechanical drawings. Persons taking up the study of the subject by themselves 
will be able by the use of the instruction given to readily grasp the subject, and by reason¬ 
able practice become good perspective draftsmen. The arrangement of the book is good; 
the plate is on the left-hand, while the descriptive text follows on the opposite page, so as to 
be readily referred to. The drawings are on sufficiently large scale to show the work clearly 
and are plainly figured. The whole work makes a very complete course on perspective draw¬ 
ing, and will be found of great value to architects, civil and mechanical engineers, patent 
attorneys, art designers, engravers, and draftsmen. $2.50 

PRACTICAL PERSPECTIVE. By Richards and Colvin. 

Shows just how to make all kinds of mechanical drawings in the only practical perspective 
isometric. ^ Makes everything plain so that any mechanic can understand a sketch or drawing 
in this way. Saves time in the drawing room, and mistakes in the shops. Contains practical 
examples of various classes of work. 3rd Edition.. ..... 50 cents 

SELF-TAUGHT MECHANICAL DRAWING AND ELEMENTARY MACHINE 
DESIGN. By F- L. Sylvester, M.E., Draftsman, with additions by Erik Oberg, 
associate editor of “Machinery.” 

This is a practical treatise on Mechanical Drawing and Machine Design, comprising the 
first principles of geometric and mechanical drawing, workshop mathematics, mechanics, 
strength of materials and the calculations and design of machine details. The author’s 
aim has been to adapt this treatise to the requirements of the practical mechanic and young 
draftsman and to present the matter in as clear and concise a manner as possible. To 
meet the demands of this class of students, practically all the important elements of machine 
design have been dealt with, and in addition algebraic formulas have been explained, and 
the elements of trigonometry treated in the manner best suited to the needs of the prac¬ 
tical man. The book is divided into 20 chapters, and in arranging the material, mechan¬ 
ical drawing, pure and simple, has been taken up first, as a thorough understanding of the 
principles of representing objects facilitates the further study of mechanical subjects. This 
is followed by the mathematics necessary for the solution of the problems in machine de¬ 
sign which are presented later, and a practical introduction to theoretical mechanics and 
the strength of materials. The various elements entering into machine design, such as cams, 
gears, sprocket wheels, cone pulleys, bolts, screws, couplings, clutches, shafting and fly¬ 
wheels have been treated in such a way as to make possible the use of the work as a text¬ 
book for a continuous course of study. It is easily comprehended and assimilated even by 
stTidents of limited previous training. 330 pages, 215 engravings. Price. . . . $2.00 

A NEW SKETCHING PAPER. 

A new specially ruled paper to enable you to make sketches or drawings in isometric perspective 
without any figuring or fussing. It is being used for shop details as well as for assembly 
drawings, as it makes one sketch do the work of three, and no workman can help seeing just 
what is wanted. Pads of 40 sheets, 6x9 inches, 25 cents. Pads of 40 sheets, 9x12 inchee. 
50 cents; 4^sheets, 12 x 18, Price. $1.00 


8 











CATALOGUE OF GOOD, PRACTICAL BOOKS 


ELECTRICITY 


ARITHMETIC OF ELECTRICITY. By Prof. T. O’Conor Sloane. 

A practical treatise on electrical calculations of all kinds reduced to a series of rules, all of the 
simplest forms, and involving only ordinary arithmetic; each rule illustrated by one or more 
practical problems, with detailed solution of each one. This book is classed among the most 
useful works published on the science of electricity covering as it does the mathematics of 
electricity in a manner that will attract the attention of those who are not familiar with alge¬ 
braical formulas. 20th Edition. 160 pages. Price. $1.00 

COMMUTATOR CONSTRUCTION. By Wm. Baxter, Jr. 

The business end of any dynamo or motor of the direct current type is the commutator. This 
book goes into the designing, building, and maintenance of commutators, shows how to locate 
troubles and how to remedy them; everyone who fusses with dynamos needs this. 25 cents 

DYNAMO BUILDING FOR AMATEURS, OR HOW TO CONSTRUCT A FIFTY-WATT 
DYNAMO. By Arthur J. Weed, Member of N. Y. Electrical Society. 

A practical treatise showing in detail the construction of a small dynamo or motor, the entire 
machine work of which can be done on a small foot lathe. Dimensioned working drawings 
are given for each piece of machine work and each operation is clearly described. This 
machine, when used as a dynamo, has an output of fifty watts; when used as a motor it will 
drive a small drill press or lathe. It can be used to drive a sewing machine on any and all 
ordinary work. The book is illustrated with more than sixty original engravings showing 
the actual construction of the different parts. Among the contents are chapters on 1. Fifty 
Watt Dynamo. 2. Side Bearing Rods. 3. Field Punchings. 4. Bearings. 5. Commu¬ 
tator. 6. Pulley. 7. Brush Holders. 8. Connection Board. 9. Armature Shaft. 10. 
Armature. 11. Armature Winding. 12. Field Winding. 13. Connecting and Starting. 
Price, paper, 50 cents. Cloth.. .$1.00 

ELECTRIC FURNACES AND THEIR INDUSTRIAL APPLICATIONS. By J. Wright 

This is a book which will prove of interest to many classes of people; the manufacturer who 
desires to know what product can be manufactured successfully in the electric furnace, the 
chemist who wishes to post himself on the electro-chemistry, and the student of science who 
merely looks into the subject from curiosity. The book is not so scientific as to be of use 
only to the technologist, nor so unscientific as to suit only the tyro in electro-chemistry; it 
is a practical treatise of what has been done, and of what is being done, both experimentally 
and commercially with the electric furnace. 

In important processes not only are the chemical equations given, but complete thermal data 
are set forth and both the efficiency of the furnace and the cost of the product are worked 
out, thus giving the work a solid commercial value aside frorh its efficacy as a work of reference. 
The practical features of furnace building are given the space that the subject deserves. The 
forms and refractory materials used in the linings, the arrangement of the connections to the 
electrodes, and other important details are explained. 288 pages. New Revised Edition. 
Fully illustrated. Price. $3.00 

ELECTRIC LIGHTING AND HEATING POCKET BOOK. By Sydney F. Walker. 

This book puts in convenient form useful information regarding the apparatus which is likely 
to be attached to the mains of an electrical company. Tables of units and equivalents are 
included and useful electrical laws and formulas are stated. 

One section is devoted to dynamos, motors, transformers and accessory apparatus; another 
to accumulators, another to switchboards and related equipment, a fourth to a description 
of various systems of distribution, a fifth section to a discussion of instruments, both for 
portable use and switchboards; another section deals with electric lamps of various types 
and accessory appliances, and the concluding section is given up to electric heating apparatus. 
In each section a large number of commercial types are described, frequent tables of dimen¬ 
sions being included. A great deal of detail information of each line of apparatus is given 
and the illustrations shown give a good idea of the general appearance of the apparatus under 
discussion. The book also contains much valuable information for the central station engi¬ 
neer. 438 pages. 300 engravings. Bound in leather pocket book form. Price . $3.00 

ELECTRIC WIRING, DIAGRAMS AND SWITCHBOARDS. By Newton Harrison. 

\ thoroughly practical treatise covering the subject of Electric Wiring in all its branches, 
including explanations and diagrams which are thoroughly explicit and greatly simplify 
the subject. Practical every-day problems in wiring are presented and the method oi 
obtaining intelligent results clearly shown. Only arithmetic is used. Ohm s law is given 


9 










CATALOGUE OF GOOD, PRACTICAL BOOKS 


a simple explanation with reference to wiring for direct and alternating currents. The funda¬ 
mental principle of drop of potential in circuits is shown with its various applications. The 
simple circuit is developed with the position of mains, feeders and branches; their treat¬ 
ment as a part of a wiring plan and their employment in ho use-wiring clearly illustrated. 
Some simple facts about testing are included in connection with the wiring. Molding 
and conduit work are given careful consideration; and switchboards are systematically 
treated, built up and illustrated, showing the purpose they serve, for connection with the j 
circuits, and to shunt and compound wound machines. The simple principles of switchboard 
construction, the development of the switchboard, the connections of the various instru¬ 
ments including the lightning arrester, are also plainly set forth. 

Alternating current wiring is treated, with explanations of the power factor, conditions 
calling for various sizes of wire and a simple way of obtaining the sizes for single-phase, two- 
phase and three-phase circuits. This is the only complete work issued showing and telling 
you what you should know about direct and alternating current wiring. It is a ready refer¬ 
ence. The work is free from advanced technicalities and mathematics, arithmetic being used 
throughout. It is in every respect a handy, well-written, instructive, comprehensive 
volume on wiring for the wireman, foreman, contractor, or electrician. 272 pages; 105 illus¬ 
trations. Price.$1.60 

ELECTRIC TOY MAKING, DYNAMO BUILDING, AND ELECTRIC MOTOR CON¬ 
STRUCTION. By Prof. T. O'Conor Sloane. 

This work treats of the making at home of electrical toys, electrical apparatus, motors, dynamos 
and instruments in general, and is designed to bring within the reach of young and old the 
manufacture of genuine and useful electrical appliances. The work is especially designed for 
amateurs and young folks. 

Thousands of our young people are daily experimenting, and busily engaged in making electrical 
toys and apparatus of various kinds. The present work is just what is wanted to give the 
much needed information in a plain, practical manner, with illustrations to make easy the 
carrying out of the work. 19th Edition. Price.$1.00 

ELECTRICIAN’S HANDY BOOK. By Prof. T. O’Conor Sloane. 

This work of 768 pages is intended for the practical electrician who has to make things go. 
The entire field of electricity -is covered within its pages. Among some of the subjects treated 
are: The Theory of the Electric Current and Circuit, Electro-Chemistry, Primary Batteries, 
Storage Batteries, Generation and Utilization of Electric Powers, Alternating Current, Arma¬ 
ture Winding, Dynamos and Motors, Motor Generators, Operation of the Central Station 
Switchboards, Safety Appliances, Distribution of Electric Light and Power, Street Mains, 
Transformers, Arc and Incandescent Lighting, Electric Measurements, Photometry, Electric 
Railways, Telephony, Bell-Wiring, Electro-Plating, Electric Heating, Wireless Telegraphy, etc. 

It contains no useless theory; everything is to the point. It teaches you just what you want ! 
to know about electricity. It is the standard work published on the subject. Forty-one 
chapters, 610 engravings, handsomely bound in red leather with title and edges in gold. Price: 

$3.50 

ELECTRICITY IN FACTORIES AND WORKSHOPS, ITS COST AND CONVENIENCE. 

By Arthur P. Haslam. 

A practical book for power producers and power users showing what a convenience the electric J 
motor, in its various forms, has become to the modern manufacturer. It also deals with the . 
conditions which determine the cost of electric driving, and compares this with other methods 
of producing and utilizing power. 

Among the chapters contained in the book are: The Direct Current Motor; The Alternating i 
Current Motor; The Starting and Speed Regulation of Electric Motors; The Rating and a 
Efficiency of Electric Motors; The Cost of Energy as Affected by Conditions of Working, The t 
Question for the Small Power User; Independent Generating Plants; Oil and Gas Engine i< 
Plants; Steam Plants; Power Station Tariffs; The Use of Electric Power in Textile Factories; J 
Electric Power in Printing Works; The Use of Electric Power in Engineering Workshops e 
Miscellaneous Application of Electric Power; The Installation of Electric Motors; The Lighting » 
of Industrial Establishments 312 pages. Very fully illustrated. Price .... $2.50 t 

ELECTRICITY SIMPLIFIED. By Prof. T. O’Conor Sloane. 1 s 

The object of “Electricity Simplified” is to make the subject as plain as possible and to show i 
what the modern conception of electricity is; to show how two plates of different metals 
immersed in acid can send a message around the globe; to explain how a bundle of copper wire 
rotated by a steam engine can be the agent in lighting our streets, to tell what the volt ohm . 
and ampere are, and what high and low tension mean; and to answer the questions that c 
perpetually arise in the mind in this age of electricity. 172 pages. Illustrated. Price $ 1 00 j 


10 









CATALOGUE OF GOOD, PRACTICAL BOOKS 


HOUSE WIRING. By Thomas W. Poppe. 

This work describes and illustrates the actual installation of Electric Light Wiring, the manner 
in wnich the work should be done, and the method of doing it. The book can be conveniently 
carried in the pocket. It is intended for the Electrician, Helper and Apprentice. It 
solves all Wiring Problems, and contains nothing that conflicts with the rulings of the Nation¬ 
al,.R oard „ Underwriters. It gives just the information essential to the Successful 

Wiring of a Building. Among the subjects treated are: Locating the Meter. Panel Boards. 
Switches. Plug Receptacles. Brackets. Ceiling Fixtures. The Meter Connections. The 
;V rc 5- .The Steel Armored Cable System. The Flexible Steel Conduit System. The 
liidig Conduit System. A digest of the National Board of Fire Underwriters’ rules relating 
to metallic wiring systems. Various switching arrangements explained and diagrammed. 
1 he easiest method of testing the Three and Four-way circuits explained. The grounding 
of all metallic wiring systems and the reason for doing so shown and explained. The in¬ 
sulation of the metal parts of lamp fixtures and the reason for the same described and 
illustrated. 125 pages. Fully illustrated. Flexible cloth. Price. 50 cents 

HOW TO BECOME A SUCCESSFUL ELECTRICIAN- By Prof. T. O’Conor Sloane. 

Every young man who wishes to become a successful electrician should rear 1 this book. It tells 
in simple language the surest and easiest way to become a successful electrician. The studies 
to be followed, methods of work, field of operation and the requirements of the successful 
electrician are pointed out and fully explained. Every young engineer will find this an ex¬ 
cellent stepping-stone to more advanced works on electricity which he must master before 
success can be attained. Many young men become discouraged at the very outstart by 
attempting to read and study books that are far beyond their comprehension. This book 
serves as the connecting link between the rudiments taught in the public schools and the real 
study of electricity. It is interesting from cover to cover. Fifteenth edition. 202 pages. 
Illustrated. Price . $1.00 

MANAGEMENT OF DYNAMOS. By Lummis-Faterson. 

A handbook of theory and practice. This work is arranged in three parts. The first part 
covers the elementary theory of the dynamo. The second part, the construction and action 
of the different classes of dynamos in common use are described; while the third part relates 
to such matters as affect the practical management and working of dynamos and motors. 
The following chapters are contained in the book: Electrical Units; Magnetic Principles; 
Theory of the Dynamo; Armature; Armature in Practice; Field Magnets; Field Magnets in 
Practice; Regulating Dynamos; Coupling Dynamos; Installation, Running, and Maintenance 
)f Dynamos; Faults in Dynrmos; Faults in Armatures; Motors. 292 pages. 117 illustra¬ 
tions. Price. $1.60 

STANDARD ELECTRICAL DICTIONARY. By T. O’Conor Sloane. 

An indispensable work to all interested in electrical science. Suitable alike for the student 
and professional. A practical hand-book of reference containing definitions of about 5,000 
distinct words, terms and phrases. The definitions are terse and concise and include every 
term used in electrical science. Recently issued. An entirely new edition. Should be in the 
possession of all who desire to keep abreast with the progesss of this branch of science. In 
its arrangement and typography the book is very convenient. The word or term defined is 
printed in black-faced type which readily catches the eye, while the body of the page is in 
smaller but distinct type. The definitions are well worded, and so as to be understood by 
the non-technical reader. The general plan seems to be to give an exact, concise definition, 
and then amplify and explain in a more popular way. Synonyms are also given, and refer¬ 
ences to other words and phrases are made. A very complete and accurate index of fifty 
pages is at the end of the volume; and as this index contains all synonyms, and as all phrases 
are indexed in every reasonable combination of words, reference to the proper place in the 
body of the book is readily made. It is difficult to decide how far a book of this character 
is to keep the dictionary form, and to what extent it may assume the encyclopedia form. 
For some purposes, concise, exactly worded definitions are needed; for other purposes, more 
extended descriptions are required. This book seeks to satisfy both demands, and does it 
with considerable success. Complete, concise, and convenient. 682 pages. 393 illustra¬ 
tions. Twelfth edition. Price. $3.00 

SWITCHBOARDS. By William Baxter, Jr. 

This book appeals to every engineer and electrician who wants to know the practical side of 
things. It takes up all sorts and conditions of dynamos, connections and circuits and shows 
by diagram and illustration just how the switchboard should be connected. Includes direct 
and alternating current boards, also those for arc lighting, incandescent, and power circuits. 
Special treatment on high voltage boards for power transmission. 2d Edition. 190 pages. 
Illustrated. Price... $1.50 


II 









CATALOGUE OF GOOD, PRACTICAL BOOKS 


TELEPHONE CONSTRUCTION, INSTALLATION, WIRING, OPERATION AND 
MAINTENANCE. By W. H. IIadcliffe and H. C. Cushing. 

This book gives the principles of construction gnd operation of both the Bell and Independent 
instruments; approved methods of installing and wiring them; the means of protecting them 
from lightning and abnormal currents; their connection together for operation as series or 
bridging stations; and rules for their inspection and maintenance. Line wiring and the wir¬ 
ing and operation of special telephone systems are also treated. 

Intricate mathematics are avoided, and all apparatus, circuits and systems are thoroughly 
described. The appendix contains definitions of units and terms used in the text. Selected 
wiring tables, which are very helpful, are also included. Among the subjects treated are 
Construction, Operation, and installation of Telephone Instruments, Inspection and Main¬ 
tenance of Telephone Instruments; Telephone Line Wiring; Testing Telephone Line Wires 
and Cables; Wiring and Operation of Special Telephone Systems, etc. 100 pages, 125 illus¬ 
trations.$1.00 

WIRELESS TELEGRAPHY AND TELEPHONY SIMPLY EXPLAINED. 

By Alfred P. Morgan. 

This is undoubtedly one of the most complete and comprehensible treatises on the subject 
ever published, and a close study of its pages will enable one to master all the details of the 
wireless transmission of messages. The author has filled a long felt want and has succeeded 
in furnishing a lucid, comprehensible explanation in simple language of the theory and 
practice of wireless telegraphy and telephony. 

Among the contents are: Introductory; Wireless Transmission and Reception—The 
Aerial System, Earth Connections—The Transmitting Apparatus, Spark Coils and Trans¬ 
formers, Condensers, Helixes, Spark Gaps, Anchor Gaps, Aerial Switches—The Receiving 
Apparatus, Detectors, etc.—Tuning and Coupling, Tuning Coils, Loose Couplers, Variable 
Condensers, Directive Wave Systems—Miscellaneous Apparatus, Telephone Receivers, 
Range of Stations, Static, Interference—Wireless Telephones, Sound and Sound Waves, The 
Vocal Cords and Ear—Wireless Telephones, How Sounds are changed into Electric Waves— 
Wireless Telephones, The Apparatus—Summary. 200 pages. 150 engravings. Price $1.00 

WIRELESS TELEPHONES AND HOW THEY WORK. By James Erskine-Murray. 

This work is free from elaborate details and aims at giving a clear survey of the way in whicb 
Wireless Telephones work. It is intended for amateur workers and for those-whose knowledge 
of electricity is slight. Chapters contained: How We Hear; Historical; The Conversion ol 
Sound into Electric Waves; Wireless Transmission; The Production of Alternating Currents 
of High Frequency; How the Electric Waves are Radiated and Received; The Receiving 
Instruments; Detectors; Achievements and Expectations; Glossary of Technical Words, 
Cloth. Price. $1.00 

WIRING A HOUSE. By Herbert Pratt. 

Shows a house already built; tells just how to start about wiring it; where to begin; what 
wire to use; how to run it according to Insurance Rules; in fact just the information you need. 
Directions apply equally to a shop. Fourth edition. 26 cents 


FACTORY MANAGEMENT, ETC. 


MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. 

By O. E. Perrigo, M.E. 

The only work published that describes the modern machine shop or manufacturing plant from 
the time the grass is growing on the site intended for it until the finished product is shipped. 
By a careful study of its thirty-two chapters the practical man may economically build 
efficiently equip, and successfully manage the modern machine shop or manufacturing estab- 
ishment. Just the book needed by those contemplating the erection of modern shop buildings, 
the re-building and re-organization of old ones, or the introduction of modern shop methods’ 
time and cost system. It is a book written and illustrated by a practical shop man for practical 
shop men who are too busy to read theories and want facts. It is the most complete all around 
book of its kind ever published. It is a practical book for practical men, from the apprentice 
in the shop to the president in the office. It minutely describes and illustrates the most simple 
and yet the most efficient time and cost system yet devised. Price. $6.00 


12 












CATALOGUE OF GOOD, PRACTICAL BOOKS 


FUEL 


COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By Wm. M. Barr. 

This book has been prepared with special reference to the generation of heat by the combus¬ 
tion of the common fuels found in the United States, and deals particularly with the condi¬ 
tions necessary to the economic and smokeless combustion of bituminous coals in Stationary 
and Locomotive Steam Boilers. 

The presentation of this important subject is systematic and progressive. The arrangement 
of the book is in a series of practical questions to which are appended accurate answers, 
which describe in language, free from technicalities, the several processes involved in the 
furnace combustion of American fuels; it clearly states the essential requisites for perfect 
combustion, and points out the best methods for furnace construction for obtaining the great¬ 
est quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. 
Price.'. $1.00 

SMOKE PREVENTION AND FUEL ECONOMY. By Booth and Kershaw. 

A complete treatise for all interested in smoke prevention and combustion, being based on 
the German work of Ernst Schmatolla, but it is more than a mere translation of the German 
treatise, much being added. The authors show as briefly as possible the principles of fuel 
combustion, the methods which have been and are at present in use, as well as the proper 
scientific methods for obtaining all the energy in the coal and burning it without smoke. 
Considerable space is also given to the examination of the waste gases, and several of the 
representative English and American mechanical stoker and similar appliances are described. 
The losses carried away in the waste gases are thoroughly analyzed and discussed in the Ap¬ 
pendix, and abstracts are also here given of various patents on combustion apparatus. Tne 
Book is complete and contains much of value to all who have charge of large plants. 194 
pages. Illustrated. Price. $2.50 


GAS ENGINES AND GAS 


GASOLINE ENGINES: THEIR OPERATION, USE AND CARE. By A. Hyatt 

Verrill. 

The Simplest, Latest and Most Comprehensive popular work published on Gasoline Engines 
describing what the Gasoline engine is; its construction and operation; how to install it; 
how to select it; how to use it and how to remedy troubles encountered. Intended for owners, 
Operators and Users of Gasoline Motors of all kinds. This work fully describes and illus¬ 
trates the various types of Gasoline engines used in Motor Boats, Motor Vehicles and 
Stationary Work. The parts, accessories and Appliances are described, with chapters on 
ignition, fuel, lubrication, operation and engine troubles. Special attention is given to the 
care, operation and repair of motors with useful hints and suggestions on emergency re¬ 
pairs and make-shifts. A complete glossary of technical terms and an alphabetically ar¬ 
ranged table of troubles and their symptoms form most valuable and unique features of this 
manual. Nearly every illustration in the book is original, having been made by the author. 
Every page is full of interest and value. A book which you cannot afford to be without. 320 
pages. Nearly 150 specially made engravings. Price. $1.50 


GAS, GASOLINE, AND OIL ENGINES. By Gardner D. Hiscox. 

Just issued, 20th revised and enlarged edition. Every user of a gas engine needs this book. 
Simple, instructive, and right up-to-date. The only complete work on the subject. Tells 
all about the running and management of gas, gasoline and oil engines, as designed and manu¬ 
factured in the United States. Explosive motors for stationary, marine and vehicle power are 
fully treated, together with illustrations of their parts and tabulated sizes, also their care and 
running are included. Electric ignition by induction coil and jump spark are fully explained 
and illustrated, including valuable information on the testing for economy and power and the 
erection of power plants. 

The rules and regulations of the Board of Fire Underwriters in regard to the installation and 
management of gasoline motors is given in full, suggesting the safe installation of explosive 
motor power. A list of United States Patents issued on gas, gasoline, and oil engines and their 
adjuncts from 1875 to date is included. 484 pages. 410 engravings Price . . . $2.50 


MODERN GAS ENGINES AND PRODUCER GAS PLANTS. By R. E. Mathot, M.E. 

A guide for the gas engine designer, user, and engineer in the construction, selection, purchase 
installation, operation, and maintenance of gas engines. More than one book on gas engines 
has been written, but not one has thus far even encroached on the field covered by this book. 
Above all Mr. Mathot’s work is a practical guide. Recognizing the need of a volume that 


*3 











CATALOGUE OF GOOD, PRACTICAL BOOKS 


would assist the gas engine user in understanding thoroughly the motor upon which he depends 
for power, the author has discussed his subject without the help of any mathematics and 
without elaborate theoretical explanations. Every part of the gas engine is described in detail, 
tersely, clearly, with a thorough understanding of the requirements of the mechanic. Helpful 
suggestions as to the purchase of an engine, its installation, care, and operation form a most 
valuable feature of the work. 320 pages. 175 detailed illustrations. Price . . . $2.50 

GAS ENGINE CONSTRUCTION, OR HOW TO BUILD A HALF-HORSE-POWER 
GAS ENGINE. By Parsell and Weed. 

A practical treatise of 300 pages describing the theory and principles of the action of Gas 
Engines of various types and the design and construction of a half-horse power Gas Engine, with 
illustrations of the work in actual progress, together with the dimensioned working drawings 
giving clearly the sizes of the various details; for the student, the scientific investigator and the 
amateur mechanic. 

Tnis book treats of the subject more from the standpoint of practice than that of theory. The 
principles of operation of Gas Engines are clearly and simply described and then the actual 
construction of a half-horse power engine is taken up, step by step, showing in detail the making 
of the Gas Engine. 3d Edition. 300 pages. Price. $2.50 

THE GASOLINE ENGINE ON THE FARM: ITS OPERATION, REPAIR 
AND USES. By Xeno W. Putnam. 

This is a practical treatise on the Gasoline and Kerosene engine intended for the man who 
wants to know just how to manage his engine and how to apply it to all kinds of farm work 
to the best advantage. 

The book includes selecting the most suitable engine for farm work, its most convenient and 
efficient installation, with chapters on troubles, their remedies and how to avoid them. 
The care and management of the farm tractor in plowing, harrowing, harvesting and road 
grading are fully covered; also plain directions are given for handling the tractor on the road. 
Special attention is given to relieving farm life of its drudgery by applying power to the 
disagreeable small tasks which must otherwise be done by hand. Many homemade con¬ 
trivances for cutting wood, supplying kitchen, garden and barn with water, loading, hauling 
and unloading hay, delivering grain to the bins or the feed trough are included; also full 
directions for making the engine milk the cows, churn, wash, sweep the house and clean the 
windows, etc. Very fully illustrated with drawings of working parts and cuts showing 
Stationary, Portable and Tractor Engines doing all kinds of farm work. 300 pages. Nearly 
150 engravings. 12mo. Price. . $1.50 

CHEMISTRY OF GAS MANUFACTURE. By H. M. Royles. 

This book covers points likely to arise in the ordinary course of the duties of the engineer or 
manager of a gas works not large enough to necessitate the employment of a separate chemical 
staff. It treats of the testing of the raw materials employed in the manufacture of illuminat¬ 
ing coal gas, and of the gas produced. The preparation of standard solutions is given as well 
as the chemical and physical examination of gas coal including among its contents—Prepa¬ 
rations of Standard Solutions, Coal, Furnaces, Testing and Regulation. Products of Car¬ 
bonization. Analysis of Crude Coal Gas. Analysis of Lime. Ammonia. Analysis of Oxide 
of Iron. Naphthalene. Analysis of Fire-Bricks and Fire-Clay. Weldom and Spent Oxide. 
Photometry and Gas Testing. Carburetted Water Gas. Metropolis Gas. Miscellaneous 
Extracts. Useful Tables. $4.50 

GEARING AND CAMS 


BEVEL GEAR TABLES. By D. Ag. Engstrom. 

A book that will at once commend itself to mechanics and draftsmen. Does away with all 
the trigonometry and fancy figuring on bevel gears and makes it easy for anyone to lay them 
out or make them just right. There are 36 full-page tables that show every necessary dimen¬ 
sion for all sizes or combinations you’re apt to need. No puzzling figuring or guessing. 
Gives placing distance, all the angles (including cutting angles), and the correct cutter to use 
A copy of this prepares you for anything in the bevel gear line. 66 pages. . $1.00 

CHANGE GEAR DEVICES. By Oscar E. Perrigo. 

A practical book for every designer, draftsman, and mechanic interested in the invention and 
development of the devices for feed changes on the different machines requiring such mechan¬ 
ism. All the necessary information on this subject is taken up, analyzed, classified, sifted 
and concentrated for the use of busy men who have not the time to go through the masses 
of irrelevant matter with which such a subject is usually encumbered and select such infor¬ 
mation as will be useful to them. 

It shows just what has been done, how it has been done, when it was done, and who did it 
It saves time in hunting up patent records and re-inventing old ideas. 88 pages. $1.00 


14 










CATALOGUE OF GOOD. PRACTICAL BOOKS 


DRAFTING OF CAMS. By Louis Rouillion. 

The laying out of cams is a serious problem unless you know how to go at it right. This puts 
you on the right road for practically any kind of cam you are likely to run up against. 25 cents 

HYDRAULICS 


HYDRAULIC ENGINEERING. By Gardner D. Hiscox. 

A treatise on the properties, power, and resources of water for all purposes. Including the 
measurement of streams, the flow of water in pipes or conduits; the horse-power of falling 
water; turbine and impact water-wheels, wave motors, centrifugal, reciprocating, and air¬ 
lift pumps. With 300 figures and diagrams and 36 practical tables. 

All who are interested in water-works development will find this book a useful one, because 
it is an entirely practical treatise upon a subject of present importance, and cannot fail in 
having a far-reaching influence, and for this reason should have a place in the working library 
of every engineer. Among the subjects treated are: Historical—Hydraulics, Properties of 
Water; Measurement of the flow of Streams; Flow from Subsurface orifices and nozzles; 
Flow of water in Pipes; Siphons of various kinds; Dams and Great Storage Reservoirs; 
City and Town Water Supply; Wells and their reenforcement; Air lift methods of raising 
water; artesian wells; Irrigation of Arid districts; Water Power, Water Wheels; Pumps and 
Pumping Machinery; Reciprocating Pumps; Hydraulic Power Transmission; Hydraulic 
Mining; Canals; Ditches; Conduits and Pipe Lines; Marine Hydraulics; Tidal and Sea 
Wave power, etc. 320 pages. Price.$4.00 


ICE AND REFRIGERATION 


POCKET BOOK OF REFRIGERATION AND ICE MAKING. By A. J. Wallis- 
Taylor. 

This is one of the latest and most comprehensive reference books published on the subject of 
refrigeration and cold storage. It explains the properties and refrigerating effect of the different 
fluids in use, the management of refrigerating machinery and the construction and insulation 
of cold rooms with their required pipe surface for different degrees of cold; freezing mixtures 
and non-freezing brines, temperatures of cold rooms for all kinds of provisions, cold storage 
charges for all classes of goods, ice making and storage of ice, data and memoranda for constant 
reference by refrigerating engineers, with nearly one hundred tables containing valuable 
references to every fact and condition required in the installment and operation of a refrigerat¬ 
ing plant. Illustrated. (5th Edition, revised.) Price.$1.50 

INVENTIONS—PATENTS 


INVENTOR’S MANUAL, HOW TO MAKE A PATENT PAY. 

This is a book designed as a guide to inventors in perfecting their inventions, taking out their 
patents and disposing of them. It is not in any sense a Patent Solicitor’s Circular, nor a 
Patent Broker’s Advertisement. No advertisements of any description appear in the work. 
It is a book containing a quarter of a century’s experience of a successful inventor, together 
with notes based upon the experience of many other inventors. 

Among the subjects treated in this work are: How to Invent. How to Secure a Good 
Patent. Value of Good Invention. How to exhibit an Invention. How to Interest 
Capital. How to Estimate the Value of a Patent. Value of Design Patents. Value of 
Foreign Patents. Value of Small Inventions. Advice on Selling Patents. Advice on the 
Formation of Stock Companies. Advice on the Formation of Limited Liability Companies. 
Advice on Disposing of Old Patents. Advice as to Patent Attorneys. Advice as to Selling 
Agents. Forms of Assignments. License and Contracts. State Laws Concerning Patent 
Rights. 1900 Census of the United States by counties of over 10,000 population. Revised 
edition. 120 pages. Price.. 


KNOTS 


KNOTS, SPLICES AND ROPE WORK. By A. Hyatt Verrill. 

This is a practical book giving complete and simple directions for making all the most use¬ 
ful and ornamental knots in common use. with chapters on Splicing, Pointing, Seizing, 


















CATALOGUE OF GOOD, PRACTICAL BOOKS 


Serving, etc. This book is fully illustrated with one hundred and fifty original engravings 
which show how each knot, tie or splice is formed and its appearance when finished. The 
book will be found of the greatest value to Campers, Yachtsmen, Travelers, Boy Scouts 
in fact to anyone having occasion to use or handle rope or knots for any purpose. The book 
is thoroughly reliable and practical and is not only a guide but a teacher. It is the standard 
work on the subject. Among the contents are: 1. Cordage, Kinds of Rope. Construction 
of Rope, Parts of Rope Cable and Bolt Rope. Strength of Rope, Weight of Rope. 2. Sim¬ 
ple knots and Bends. Terms used in Handling Rope. Seizing Rope. 3. Ties and Hitches. 
4. Noose, Loops and Mooring Knots. 5. Shortenings, Grommets and Selvages. 6. Lash¬ 
ings. Seizings and Splices. 7. Fancy Knots and Rope Work. 128 pages. 150 original 
engravings. Price. 60 cents 


LATHE WORK 


MODERN AMERICAN LATHE PRACTICE. By Oscar E. Perrigo. 

This is a new book from cover to cover, and the only complete American work on the subject 
written by a man who knows not only how work ought to be done, but who also knows 
how to do it, and how to convey this knowledge to others. It is strictly up-to-date in its 
descriptions and illustrations, which represent the very latest practice in lathe and boring 
mill operations as well as the construction of and latest developments in the manufacture 
of these important classes of machine tools. 

Lathe history and the relations of the Lathe to manufacturing are given; also a description 
of the various devices for Feeds and Thread Cutting mechanisms from early efforts in this 
direction to the present time. Lathe design is thoroughly discussed, including Back Gearing, 
Driving Cones, Thread Cutting Gears, and all the essential elements of the modern Lathe. 
The classification of Lathes is taken up, giving the essential differences of the several types 
of Lathes, including, as is usually understood, Engine Lathes, Bench Lathes, Speed Lathes, 
Forge Lathes, Gap Lathes, Pulley Lathes, Forming Lathes, Multiple Spindle Lathes, Rapid 
Reduction Lathes, Precision Lathes, Turret Lathes, Special Lathes, Electrically Driven 
Lathes, etc. 424 pages. 314 illustrations. Price. . $2.60 

PRACTICAL METAL TURNING. By Joseph G. Horner. 

This important and practical subject is treated in a full and exhaustive manner and nothing 
of importance is omitted. The principles and practice and all the different branches of Turn¬ 
ing are considered and well illustrated. All the different kinds of Chucks of usual forms, as 
well as some unusual kinds, are shown. A feature of the book is the important section de¬ 
voted to modern Turret practice; Boring is another subject which is treated fully; and the 
chapter on Tool Holders illustrates a large number of representative types. Thread Cutting 
is treated at reasonable length; and the last chapter contains a good deal of information 
relating to the High-Speed Steels and their work. The numerous tools used by machinists 
are illustrated, and also the adjuncts of the lathe. In fact, the entire subject is treated in 
such a thorough manner as to make this book the standard one on the subject. It is indis¬ 
pensable to the manager, engineer, and machinist as well as to the student, amateur, and 
experimental man who desires to keep up-to-date. 400 pages, fully illustrated. Price $3.50 

TURNING AND BORING TAPERS. By Fred H. Colvin. 

There are two ways to turn tapers; the right way and one other. This treatise has to do with 
the right way; it tells you how to start the work properly, how to set the lathe, what tools to 
use and how to use them, and forty and one other little things that y >u should know. Fourth 
edition. 25 cents 


LIQUID AIR 


LIQUID AIR AND THE LIQUEFACTION OF GASES. By T. O’Conor Sloane. 

This book gives the history of the theory, discovery, and manufacture of Liquid Air, and 
contains an illustrated description of all the experiments that have excited the wonder of 
audiences all over the country. It shows how liquid air, like water, is carried hundreds of 
miles and is handled in open buckets. It tells what may be expected from it in the near 
future. 

A book that renders simple one of the most perplexing chemical problems of the century. 
Startling developments illustrated by actual experiments. 

It is not only a work of scientific interest and authority, but is intended for the general reader, 
being written in a popular «tyle—easily understood by every one. Second edition. 365 
pages. Price ... . $2.00 














CATALOGUE OF GOOD, PRACTICAL BOOKS 


£ 


LOCOMOTIVE ENGINEERING 


AIR-BRAKE CATECHISM. By Robert H. Blackall. 

This book is a standard text book. It covers the Westinghouse Air-Brake Equipment, in¬ 
cluding the No. 5 and the No. 6 E. T Locomotive Brake Equipment; the K (Quick-Service) 
Triple Valve for Freight Service; and the Cross-Compound Pump. The operation of all parts 
of the apparatus is explained in detail, and a practical way of finding their peculiarities and 
defects, with a proper remedy, is given. It contains 2,000 questions with their answers, 
which will enable any railroad man to pass any examination on the subject of Air Brakes. 
Endorsed and used by air-brake instructors and examiners on nearly every railroad in the 
United States. 25th Edition. 350 pages, fully illustrated with folding plates and dia¬ 
grams.$2.00 


AMERICAN COMPOUND LOCOMOTIVES. By Fred. H. Colvin. 

The only book on compounds for the engineman or shopman that shows in a plain, practical 
way the various features of compound locomotives in use. Shows how they are made, what 
to do when they break down or balk. Contains sections as follows:—A Bit of History. The¬ 
ory of Compounding Steam Cylinders. Baldwin Two-Cylinder Compound. Pittsburg Two- 
. Cylinder Compound. Rhode Island Compound. Richmond Compound. Rogers Compound. 
[Schenectady Two-Cylinder Compound. Vauclain Compound. Tandem Compounds. Bald¬ 
win Tandem. The Colvin-Wightman Tandem. Schenectady Tandem. Balanced Loco¬ 
motives. Baldwin Balanced Compound. Plans for Balancing. Locating Blows. Break¬ 
downs. Reducing Valves. Drifting. Valve Motion. Disconnecting. Power of Compound 
Locomotives. Practical Notes. 

Fully illustrated [and containing ten special “Duotone” inserts on heavy Plate Paper, show¬ 
ing different types of Compounds. 142 pages. Price.$1.00 


APPLICATION OF HIGHLY SUPERHEATED STEAM TO LOCOMOTIVES. By 

Robert Garbe. 

A practical book. Contains special chapters on Generation of Highly Superheated Steam; 
Superheated Steam and the Two-Cylinder Simple Engine; Compounding and Superheating; 
Designs of) Locomotive Superheaters; Constructive Details of Locomotives using Highly 
Superheated Steam; Experimental and Working Results. Illustrated with folding plate* 
and tables. Price. $ 2.60 


COMBUSTION OF COAL AND^ THE PREVENTION OF SMOKE. 


By Wm. M. Barr. 

This book has been prepared with special reference to the generation of heat by the combus¬ 
tion of the common fuels found in the United States, and deals particularly with the condi¬ 
tions necessary to the economic and smokeless combustion of bituminous coal in Stationary 
and Locomotive Steam Boilers. 


The presentation of this important subject is systematic and progressive. The arrangement 
of the book is in a series of practical questions to which are appended accurate answers, 
which describe in language, free from technicalities, the several processes involved in the 
furnace combustion of American fuels; it clearly states the essential requisites for perfect 
combustion and points out the best methods of furnace construction for obtaining the 
greatest quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. 
Price.. 


DIARY OF A ROUND HOUSE FOREMAN. By T. S. Reilly . 

This is the greatest book of railroad experiences ever published. Containing a fund of infor¬ 
mation and suggestions along the line of handling men, organizing, etc., that one cannot afford 
to miss. 176 pages. Price.. 


LINK MOTIONS, VALVES AND VALVE SETTING. By Fred H. Colvin, Associate 
Editor of “American Machinist.” 


A handv book for the engineer or machinist that clears up the mysteries of valve setting. 
Shows the different valve gears in use, how they work, and why. Piston and slide valves 
of different types are illustrated and explained. A book that every railroad man in the mo¬ 
tive power department ought to have. Contains chapters on Locomotive Link Motion 
Valve P Movements, Setting Slide Valves, Analysis by Diagrams Modern Practice, Slip of 
Block Slide Valves, Piston Valves, Setting Piston Valves Joy-Alien Valve Gear, Walschaert 
VaWe Gear Gooch Valve Gear, Alfree-Hubbell Valve Gear, etc., etc. Fully illustrated. 


Price 


50 cents 


*7 












CATALOGUE OF GOOD, PRACTICAL BOOKS 


LOCOMOTIVE BOILER CONSTRUCTION. By Frank A. Kleinhans. 

The construction of boilers in general is treated, and following this, the locomotive boiler 
is taken up in the order in which its various parts go through the simp. Shows all types of 
boilers used; gives details of construction; practical facts, such as life of riveting, punches 
and dies; work done per day, allowance for bending and flanging sheets, and other data. 
Locomotive boilers present more difficulty in laying out and building than any other type, 
and for this reason the author uses them as examples. Anyone who can handle them can 
tackle anything. 

Contains chapters on Laying Out Work; Flanging and Forging; Punching; Shearing; Plate 
Planing; General Tables; Finishing Parts; Bending; Machinery Parts; Riveting; Boiler 
Details; Smoke Box Details; Assembling and Calking; Boiler Shop Machinery, etc., etc. 
There isn’t a man who has anything to do with boiler work, either new or repair work, who 
doesn’t need this book. The manufacturer, superintendent, foreman, and boiler worker 
all need it. No matter what the type of boiler, you’ll find a mint of information that you 
wouldn’t be without. Over 400 pages, five large folding plates. Price. $ 3.00 

LOCOMOTIVE BREAKDOWNS AND THEIR REMEDIES. By Geo. L. Fowler. 

Revised by Wm. W. Wood, Air-Brake Instructor. Just issued. Revised pocket 
edition. 

It is out of the question to try and tell you about every subject that is covered in this pocket 
edition of Locomotive Breakdowns. Just imagine all the common troubles that an engineer 
may expect to happen some time, and then add all of the unexpected ones, troubles that could 
occur, but that you had never thought about, and you will find that they are all treated with 
the very best methods of repair. Walschaert Locomotive Valve Gear Troubles, Electric 
Headlight Troubles, as well as Questions and Answers on the Air Brake are all included. 294 
pages. 7th Revised Edition. Fully illustrated. $ 1.00 

LOCOMOTIVE CATECHISM. By Robert Grimshaw. 

The revised edition of “Locomotive Catechism,” by Robert Grimshaw, is a New Book from 
Cover to Cover. It contains twice as many pages and double the number of illustrations 
of previous editions. Includes the greatest amount of practical information ever published 
on the construction and management of modern locomotives. Specially Prepared Chapters 
on the Walschaert Locomotive Valve Gear, the Air Brake Equipment and the Electric Head 
Light are given. 

It commends itself at once to every Engineer and Fireman, and to all who are going in for 
examination or promotion. In plain language, with full complete answers, not only all the 
questions asked by the examining engineer are given, but those which the young and less 
experienced would ask the veteran, and which old hands ask as “stickers.” It is a veritable 
Encyclopedia of the Locomotive, is entirely free from mathematics, easily understood and 
thoroughly up-to-date. Contains over 4,000 Examination Questions with their Answers. 
825 pages, 437 illustrations and three folding plates. 28th Revised Edition. . . $ 2.50 

PRACTICAL INSTRUCTOR AND REFERENCE BOOK FOR LOCOMOTIVE 
FIREMEN AND ENGINEERS. By Chas. F. Lockhart. 

An entirely new book on the Locomotive. It appeals to every railroad man, as it tells him 
how things are done and the right way to do them. Written by a man who has had years 
of practical experience in locomotive shops and on the road firing and running. The infor¬ 
mation given in this book cannot be found in any other similar treatise. Eight hundred and 
fifty-one questions with their answers are included, which will prove specially helpful to 
those preparing for examination. Practical information on: The Construction and Opera¬ 
tion of Locomotives. Breakdowns and their Remedies; Air Brakes and Valve Gears. 
Rules and Signals are handled in a thorough manner. As a book of reference it cannot be 
excelled. The book is divided into six parts, as follows: 1. The Fireman’s Duties. 2. 
General description of the Locomotive. 3. Breakdowns and their Remedies. 4. Air Brakes. 
5. Extracts from Standard Rules. 6. Questions for examination. The 851 questions have 
been carefully selected and arranged. These cover the examinations required by the different 
railroads. 368 pages. 88 illustrations. Price. $ 1.50 

PREVENTION OF RAILROAD ACCIDENTS, OR SAFETY IN RAILROADING. 

By George Bradshaw. 

This book is a heart-to-heart talk with Railroad Employees, dealing with facts, not theories, 
and showing the men in the ranks, from every-day experience, how accidents occur and how 
they may be avoided. The book is illustrated with seventy original photographs and draw¬ 
ings showing the safe and unsafe methods of work. No visionary schemes, no ideal pictures. 
Just plain facts and Practical Suggestions are given. Every railroad employee who reads the 

l8 









CATALOGUE OF GOOD, PRACTICAL BOOKS 


book is a better and safer man to have in railroad service. It gives just the information 
which will be the means of preventing many injuries and deaths. All railroad employees 
should procure a copy, read it, and do your part in preventing accidents. 169 pages. Pocket 
Size. Fully illustrated. Price.50 cents 

TRAIN RULE EXAMINATIONS MADE EASY. By G. E. Collingwood. 

This is the only practical work on train-rules in print. Every detail is covered, and puzzling 
points are explained in simple, comprehensive language, making it a practical treatise for 
the Train Dispatcher, Engineman, Trainman, and all others who ha Tr e to do with the move¬ 
ments of trains. Contains complete and reliable information of the Standard Code of Train 
Rules for single track. Shows Signals in Colors, as used on the different roads. Explains 
fully the practical application of train orders, giving a clear and definite understanding of all 
orders which may be used. The meaning and necessity for certain rules are explained in 
such a manner that the student may know beyond a doubt the rights conferred under any 
orders he may receive or the action required by certain rules. 

As nearly all roads require trainmen to pass regular examinations, a complete set of examina¬ 
tion questions, with their answers, are included. These will enable the student to pass the 
required examinations with credit to himself and the road for which he works. 256 pages. 
Fully illustrated with Train Signals in colors. Price. $ 1.25 

TRAIN RULES AND DESPATCHING. By H. A. Dalby. 

Every railroad man, no matter what department he’s in, needs a copy of this book. It gives 
the standard rules for both single and double track, shows all the signals, with colors wher¬ 
ever necessary, and has a list of towns where time changes, with a map showing the whole 
country. The rules are explained wherever there is any doubt about their meaning or where 
they are modified by different railroads. It’s the only practical book on train rules in print. 
Over 220 pages. Leather cover. Price.$1.50 

THE WALSCHAERT AND OTHER MODERN RADIAL VALVE GEARS FOR 
LOCOMOTIVES. By Wm. W. Wood. 

If you would thoroughly understand the Walschaert Valve Gear you should possess a copy 
of this book, as the author takes the plainest form of a steam engine—a stationary engine in 
the rough, that will only turn its crank in one direction—and from it builds up—with the 
reader’s help—a modern locomotive equipped with the Walschaert Valve Gear, complete. 
The points discussed are clearly illustrated; two large folding plates that show the positions 
of the valves of both inside or outside admission type, as well as the links and other parts of 
the gear when the crank is at nine different points in its revolution, are especially valuable 
in making the movement clear. These employ sliding cardboard models which are contained 
in a pocket in the cover. 

The book is divided into five general divisions, as follows: I. Analysis of the gear. II. De¬ 
signing and erecting the gear. III. Advantages of the gear. IV. Questions and answers 
relating to the Walschaert Valve Gear. V. Setting valves with the Walschaert Valve Gear; 
the three primary types of locomotive valve motion; modern radial valve gears other than 
the Walschaert; the Hobart All-free valve and valve gear, with questions and answers on 
breakdowns; the Baker-Pilliod valve gear; the Improved Baker-Pilliod Valve Gear, with 
questions and answers on breakdowns. 

The questions with full answers given will be especially valuable to firemen and engineers 
in preparing for an examination for promotion. 245 pages. Third. Revised Edition. 

Price. $ 1.60 

WESTINGHOUSE E—T AIR-BRAKE INSTRUCTION POCKET BOOK. By Wm. 

W. Wood, Air-Brake Instructor. 

Here is a book for the railroad man, and the man who aims to be one. It is without doubt 
the only complete work published on the Westinghouse E-T Locomotive Brake Equipment. 
Written by an Air Brake Instructor who knows just what is needed. It covers the subject 
thoroughly. Everything about the New Westinghouse Engine and Tender Brake Equip¬ 
ment, including the Standard No. 5 and the Perfected No. 6 Style of brake, is treated in de¬ 
tail. Written in plain English and profusely illustrated with Colored Plates, which enable 
one to trace the flow of pressures throughout the entire equipment. The best book ever 
published on the Air Brake. Equally good for the beginner and the advanced engineer 
Will pass any one through any examination. It informs and enlightens you on every point 
Indispensable to every engineman and trainman. 

Contains examination questions and answers on the E-T equipment. Covering what the 
E-T Brake is. How it should be operated. What to do when defective. Not a question can 
be asked of the engineman up for promotion on either the No. 5 or the No. 6 E-T equipment 
that is not asked and answered in (he book. If you want to thoroughly understand the E-T 
equipment get a copy of this book. It covers every detail. Makes Air Brake troubles and 
examinations easy. Price. $ 1.60 


l 9 











CATALOGUE OF GOOD, PRACTICAL BOOKS 




MACHINE SHOP PRACTICE 


aMERICAN TOOL MAKING AND INTERCHANGEABLE MANUFACTURING. By 

J. V. Woodworth. 

A “shoppy” book, containingnotheorizing.no problematical or experimental devices, there 
are no badly proportioned and impossible diagrams, no catalogue cuts, but a valuable collec¬ 
tion of drawings and descriptions of devices, the rich fruits of the author’s own experience. 
In its 500-odd pages the one subject only, Tool Making, and whatever relates thereto, is 
dealt with. The work stands without a rival. It is a complete practical treatise on the 
art of American Tool Making and system of interchangeable manufacturing as carried on 
to-day in the United States. In it are described and illustrated all of the different types 
and classes of small tools, fixtures, devices, and special appliances which are in general use 
in all machine manufacturing and metal working establishments where economy, capacity, 
and interchangeability in the production of machined metal parts are imperative. The 
science of jig making is exhaustively discussed, and particular attention is paid to drill jigs, 
boring, profiling and milling fixtures and other devices in which the parts to be machined 
are located and fastened within the contrivances. All of the tools, fixtures, and devices 
illustrated and described have been or are used for the actual production of work, such as 
parts of drill presses, lathes, patented machinery, typewriters, electrical apparatus, mechan¬ 
ical appliances, brass goods, composition parts, mould products, sheet metal articles, drop 
forgings, jewelry, watches, medals, coins, etc. 531 pages. Price. $ 4.00 

HENLEY’S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED 
TRADES. Edited by Joseph G. Horner, A.M.I., M.E. 

This set of five volumes contains about 2,500 pages with thousands of illustrations, including 
diagrammatic and sectional drawings with full explanatory details. This work covers the 
entire practice of Civil and Mechanical Engineering. The best known expert in all branches 
of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted 
to the needs of the beginner and the self-taught practical man, as well as the mechanical en¬ 
gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be 
found a means of advancement to any progressive man. It is encyclopedic in scope, thorough 
and practical in its treatment of technical subjects, simple and clear in its descriptive matter, 
and without unnecessary technicalities or formulae. The articles are as brief as may be and 
yet give a reasonably clear and explicit statement of the subject, and are written by men who 
have had ample practical experience in the matters of which they write. It tells you all you 
want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot 
help but understand. As a work of reference it is without a peer. $ 6.00 per volume. For 
complete set of five volumes, price. $ 25.00 

MACHINE SHOP ARITHMETIC. By Colvin-Cheney. 

This is an arithmetic of the things you have to do with daily. It tells you plainly about: how 
to find areas of figures; how to find surface or volume of balls or spheres; handy ways for 
calculating; about compound gearing; cutting screw threads on any lathe; drilling for taps; 
speeds of drills, taps, emery wheels, grindstones, milling cutters, etc.; all about the Metric 
system with conversion tables; properties of met,als; strength of bolts and nuts; decimal 
equivalent of an inch. All sorts of machine shop figuring and 1,001 other things, any one of 
which ought to be worth more than the price of this book to you, and it saves you the trouble 
of bothering the boss. 6th Edition. 131 pages. Price. 50 cents 

MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. 

By Oscar E. Perrigo. 

The only work published that describes the Modern Machine Shop or Manufacturing Plant from 
the time the grass is growing on the site intended for it until the finished product is shipped. 
Just the book needed by those contemplating the erection of modern shop buildings, the re¬ 
building and reorganization of old ones, or the introduction of Modern Shop Methods, time and 
cost systems. It is a book written and illustrated by a practical shop man for practical shop 
men who are too busy to read theories and want facts. It is the most complete all-around 
book of its kind ever published. 400 large quarto pages. 225 original and specially-made 
illustrations. Price. $ 5.00 

MECHANICAL APPLIANCES, MECHANICAL MOVEMENTS AND NOVELTIES 
OF CONSTRUCTION. By Gardner D. Hiscox. 

This is a supplementary volume to the one upon mechanical movements. Unlike the first 
volume, which is more elementary in character, this volume contains illustrations and descrip 
tions of many combinations of motions and of mechanical devices and appliances found To 
different lines of machinery. Each device being shown bv a line drawing with a description 


20 










CATALOGUE OF GOOD, PRACTICAL BOOKS 


showing its working parts and the method of operation. From the multitude of devices de¬ 
scribed, and illustrated, might be mentioned, in passing, such items as conveyors and elevators, 
Prony brakes, thermometers,! various types of boilers, solar engines, oil-fuel burners, condensers, 
evaporators, Corliss and other valve gears, governors, gas engines, water motors of various 
descriptions, air ships, motors and dynamos, automobile and motor bicycles, railway block 
signals, car couplers, link and gear motions, ball bearings, breech block mechanism for heavy 
guns, and a large accumulation of others of equal importance. 1,000 specially made engrav¬ 
ings. 396 octavo pages. Price .$2.50 

MECHANICAL MOVEMENTS, POWERS, AND DEVICES. By Gardner D. Hiscox. 

This is a collection of 1,890 engravings of different mechanical motions and appliances, accom¬ 
panied by appropriate text, making it a book of great value to the inventor, the draftsman, 
and to all readers with mechanical tastes. The book is divided into eighteen sections or 
chapters in which the subject matter is classified under the following heads: Mechanical Powers; 
Transmission of Power; Measurement of Power, Steam Power; Air Power Appliances; Electric 
Power and Construction, Navigation and Roads; Gearing; Motion and Devices; Controlling 
Motion; Horological; Mining; Mill and Factory Appliances; Construction and Devices; 
Drafting Devices: Miscellaneous Devices, etc. 12th edition. 400 octavo pages. Price $ 2.50 

MACHINE SHOP TOOLS AND SHOP PRACTICE. By W. H. Vandervoort. 

A work of 555 pages and 673 illustrations, describing in every detail the construction, operation, 
and manipulation of both hand and machine tools. Includes chapters on filing, fitting, and 
scraping surfaces; on drills, reamers, taps, and dies; the lathe and its tools; planers, shapers, 
and their tools: milling machines and cutters; gear cutters and gear cutting; drilling machines 
and drill work; grinding machines and their work; hardening and tempering; gearing, belting 
and transmission machinery: useful data and tables. 6th edition. Price . . . , $ 3.00 

THE MODERN MACHINIST. By John T.. Usher. 

This is a book showing, by plain description and by profuse engravings, made expressly for 
the work, all that is best, most advanced, and of the highest efficiency in modern machine 
shop practice, tools, and implements, showing the way by which and through which, as Mr. 
Maxim says, “American machinists have become and are the finest mechanics in the world.” 
Indicating as it does, in every line, the familiarity of the author with every detail of daily 
experience in the shop, it cannot fail to be of service to any man nractically -connected with 
the shaping or finishing of metals. 

There is nothing experimental or visionary about the book, all devices being in actual use 
and giving good results. It might be called a compendium of shop methods, showing a vari¬ 
ety of special tools and appliances which will give new ideas to many mechanics, from the 
superintendent down to the man at the bench. It will be found a valuable addition to any 
machinist’s library, and should be consulted whenever a new or difficult job is to be done, 
whether it is boring, milling, turning, or planing, as they are all treated in a practical manner. 
Fifth Edition. 320 pages. 250 illustrations. Price ... .$ 2.50 

MODERN MILLING MACHINES: THEIR DESIGN, CONSTRUCTION AND OPERA¬ 
TION. By Joseph G. Horner. 

This book describes and illustrates the Milling Machine and its work in such a plain, clear, 
and forceful manner, and illustrates the subject so clearly and completely, that the up-to-date 
machinist, student, or mechanical engineer cannot afford to do without the valuable infor¬ 
mation which it contains. It describes not only the early machines of this class, but notes 
their gradual development into the splendid machines of the present day, giving the design 
and construction of the various types, forms, and special features produced by prominent 
manufacturers, American and foreign. 

Milling cutters in all their development and modernized forms are illustrated and described, 
and the operations they are capable of producing upon different classes of work are carefully 
described in detail, and the speeds and feeds necessary are discussed, and valuable and useful 
data given for determining these usually perplexing problems. The book is the most compre¬ 
hensive work published on the subject. 304 pages. 300 illustrations. Price . . $ 4.00 

“ SHOP KINKS.” By Robert Grimshaw. 

A book of 400 pages and 222 illustrations, being entirely different frorrt any other book on 
machine shop practice. Departing from conventional style, the author avpids universal or 
common shop usage and limits his work to showing special ways of doing things better, more 
cheaply and more rapidly than usual. As a result the advanced methods of representative 
establishments of the world are placed at the disposal of the reader. This book shows the 
proprietor where large savings are possible, and how products may be improved. To the 
employee it holds out suggestions that, properly applied, will hasten his advancement. No 
shop can afford to be without it. It bristles with valuable wrinkles and helpful suggestions. 
It will benefit all, from apprentice to proprietor. Every machinist, at any age, should study 
its pages. Fifth Edition. Price.$2.50 


2 1 









CATALOGUE OF GOOD, PRACTICAL BOOKS 


THREADS AND THREAD CUTTING. By Colvin and Stabel. 

This clears up many of the mysteries of thread-cutting, such as double and triple threads, 
internal threads, catching threads, use of hobs, etc. Contains a lot of useful hints and several 
tables. 3rd Edition. Price.36 cents 

TOOLS FOR MACHINISTS AND WOOD WORKERS, INCLUDING INSTRUMENTS 
OF MEASUREMENT. By Joseph G. Horner. 

The principles upon which cutting tools for wood, metal, and other substances are made are 
identical, whether used by the machinist, the carpenter, or by any other skilled mechanic in 
their daily work, and the object of this book is to give a correct and practical description or 
these tools as they are commonly designed, constructed, and used. 340 pages, fully illustrated. 
Price. $3.50 


MANUAL TRAINING 


ECONOMICS OF MANUAL TRAINING. By Louis Rouillion. 

The only book published that gives just the information needed by all interested in Manual 
Training, regarding Buildings, Equipment, and Supplies. Shows exactly what is needed for 
all grades of the work from the Kindergarten to the High and Normal School. Gives item¬ 
ized lists of everything used in Manual Training Work and tells just what it ought to cost. 
Also shows where to buy supplies, etc. Contains 174 pages, and is fully illustrated. 
2nd Edition. Price .. $1.50 


MARINE ENGINEERING 


MARINE ENGINES AND BOILERS, THEIR DESIGN AND CONSTRUCTION. By 

Dr. G. Bauer, Leslie S. Robertson, and S. Bryan Donkin. 


in the words of Dr. Bauer, the present work owes its origin to an oft felt want of a Condensed 
Treatise, embodying the Theoretical and Practical Rules used in Designing Marine Engines 
and Boilers. The need for such a work has been felt by most engineers engaged in the con¬ 
struction and working of Marine Engines, not only by the younger men, but also by those of 
greater experience. The fact that the original German work was written by the chief engineer 
of the famous Vulcan Works, Stettin, is in itself a guarantee that this book is in all respects 
thoroughly up-to-date, and that it embodies all the information which is necessary for the 
design and construction of the highest types of marine engines and boilers. It may be said, 
that the motive power which Dr. Bauer has placed in the fast German liners that have been 
turned out of late years from the Stettin Works, represent the very best practice in marine 
engineering of the present day. 

This work is clearly written, thoroughly systematic, theoretically sound; while the character 
of its plans, drawings, tables, and statistics is without reproach. The illustrations are care¬ 
ful reproductions from actual working drawings, with some well-executed photographic views 
of completed engines and boilers. 744 pages. 550 illustrations and numerous tables. 

$9.00 net 


MODERN SUBMARINE CHART. 


A cross-section view, showing clearly and distinctly all the interior of a Submarine of the 
latest type. You get more information from this chart, about the construction and operation 
of a Submarine, than in any other way. No Details omitted—everything is accurate and to 
scale. It is absolutely correct in every detail, having been approved by Naval Engineers. 
All the machinery and devices fitted in a modern Submarine Boat are shown and to make the 
engraving more readily understood all the features are shown in operative form with Officers 
and Men in the act of performing the duties assigned to them in service conditions. This 
CHART IS REALLY AN ENCYCLOPEDIA OF A SUBMARINE. It is educational 
and worth many times its cost. Mailed in a Tube for. 25 cents 


MINING 


ORE DEPOSITS, WITH A CHAPTER ON HINTS TO PROSPECTORS. By J. P. 

Johnson 

This book gives a condensed account of the ore-deposits at present known in South Africa. 
It is also intended as a guide to the prospector. Only an elementary knowledge of geology 
and some mining experience are necessary in order fo understand this work. With these 
qualifications, it will materially assist one in his search for metalliferous mineral occurrences 


22 














CATALOGUE OF GOOD, PRACTICAL BOOKS 


and, so far as simple ores are concerned, should enable one to form some idea of the possi¬ 
bilities of any he may find. v 

Among the chapters given are: Titaniferous and Chromiferous Iron Oxides—Nickel— Cod- 
per—Cobalt—Tm—Molybdenum—Tungsten—Lead—Mercury—Antimony—Iron—Hints to 
Prospectors.. ... $2.00 

PHYSICS AND CHEMISTRY OF MINING. By T. H. Byrom. 

A practical work for the use of all preparing for examinations in mining or qualifying for 
colliery managers’ certificates. The aim of the author in this excellent book is to place clearly 
before the reader useful and authoritative data which will render him valuable assistance in 
his studies. The only work of its kind published. The information incorporated in it will 
prove of the greatest practical utility to students, mining engineers, colliery managers and 
all others who are specially interested in the present-day treatment of mining problems 
Among its contents are chapters on: The Atmosphere; Laws Relating to the Behavior of 
Gases; The Diffusion of Gases; Composition of the Atmosphere: Sundry Constituents of the 
Atmosphere; Water; Carbon; Fire-Damp; Combustion; Coal Dust and Its Action; Ex¬ 
plosives; Composition of Various Coals and Fuels; Methods of Analysis of Coal; Strata Ad¬ 
joining the Coal Measures; Magnetism and Electricity; Appendix; Useful Tables, etc ; 
Miscellaneous Questions. 160 pages. Illustrated.. $2.00 

PRACTICAL COAL MINING. By T. H. Cockin. 

An important work, containing 428 pages and 213 illustrations, complete with practical de¬ 
tails, which will intuitively impart to the reader, not only a general knowledge of the princi¬ 
ples of coal mining, but also considerable insight into allied subjects. This treatise is posi¬ 
tively up to date in every instance, and should be in the hands of every colliery engineer, 
geologist, mine operator, superintendent, foreman, and all others who are interested in or 
connected with the industry. 2nd Edition.$2.50 

PATTERN MAKING 


PRACTICAL PATTERN MAKING. By F. W. Barrows. 

This is a very complete and entirely practical treatise on the subject of pattern making, illus¬ 
trating pattern work in wood and metal. From its pages you are taught just what you should 
know about pattern making. It contains a detailed description of the materials used by 
pattern makers, also the tools, both those for hand use, and the more interesting machine 
tools; having complete chapters on the band saw, The Buzz Saw, and the Lathe. Individual 
patterns of many different kinds are fully illustrated and described, and the mounting of 
metal patterns on plates for molding machines is included. 

Rules, Formulas and Tables are included, containing simple and original methods for finding 
the weight of castings, both from the pattern itself and from the drawings. This section 
contains some new and practical formulas, which will be found very useful in estimating 
weights, with the accuracy required for quotations to prospective customers. Ali of these 
rules are simple, and can be put to practical use by the ordinary, every-day man, and they 
have been proved by years of actual use. 

Plain rules for keeping down the cost of patterns, with a complete system for checking the 
cost of and marking the patterns, and a card record showing what the pattern is, material 
used, where-located in safe, with its cost and date of production, is included. The book closes 
with an original and practical method for the inventory and valuation of patterns. Con¬ 
taining 326 pages and 150 detailed illustrations. Price. $2.00 


PERFUMERY 


HENLEY’S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO¬ 
CESSES. Edited by G. D. Hiscox. 

The most valuable Techno-chemical Receipt Book published. Contains over 10,000 practical 
receipts, many of which will prove of special value to the perfumer, a mine of information, up- 
to-date in every respect. Price, Cloth, $3.00; half morocco.$4.00 

PERFUMES AND THEIR PREPARATION. By G. W Askinson, Perfumer. 

A comprehensive treatise, in which there has been nothing omitted that could be of value 
to the Perfumer. Complete directions for making handkerchief perfumes, smelling-salts, 
sachets, fumigating pastilles: preparations for the care of the skin, the mouth, the hair, cos¬ 
metics, hair dyes and other toilet articles are given, also a detailed description of aromatic 
substances: their nature, tests of purity, and wholesale manufacture. A book of general, 
as well as professional interest, meeting the wants not only of the druggist and perfume man¬ 
ufacturer, but also of the general public. Third edition. 312 pages. Illustrated. ; $3.00 


23 














CATALOGUE OF GOOD,. PRACTICAL BOOKS 


PLUMBING 


MECHANICAL DRAWING FOR PLUMBERS. By R. M. Starbuck. 

A concise, comprehensive and practical treatise on the subject of mechanical drawing in its 
various modern applications to the work of all who are in any way connected with the 
plumbing trade. Nothing will so help the plumber in estimating and in explaining work to 
customers and workmen as a knowledge of drawing, and to the workman it is of inestimable 
value if he is to rise above his position to positions of greater responsibility. Among the 
chapters contained are: 1. Value to plumber of knowledge of drawing; tools required 
and their use; common views needed in mechanical drawing. 2. Perspective versus mechan¬ 
ical drawing in showing plumbing construction. 3. Correct and incorrect methods in 
plumbing drawing; plan and elevation explained. 3. Floor and cellar plans and elevation; 
scale drawings; use of triangles. 5. Use of triangles; drawing of fittings, traps, etc. 6. 
Drawing plumbing elevations and fittings. 7. Instructions in drawing plumbing elevations. 
8. The drawing of plumbing fixtures; scale drawings. 9. Drawing of fixtures and fittings. 
10. Inking of drawings. 11. Shading of drawings. 12. Shading of drawings. 13. Sec¬ 
tional drawings; drawing of threads. 14. Plumbing elevations from architect’s plan. 
15. Elevations of separate parts of the plumbing system. 16. Elevations from architect’s 
plans. 17. Drawing of detail plumbing connections. 18. Architect’s plans and plumbing 
elevations of residence. 19. Plumbing elevations of residence (continued); plumbing plans 
for cottage. 20. Plumbing elevations; roof connections. 21. Plans and plumbing eleva¬ 
tions for six-flat building. 22. Drawing of various parts of the plumbing system; use of 
scales. 23. Use of architect’s scales. 24. Special features in the illustrations of country 
plumbing. 25. Drawing of wrought iron piping, valves, radiators, coils, etc. 26. Drawing 
of piping to illustrate heating systems. 150 illustrations. Price. $1.60 

MODERN PLUMBING ILLUSTRATED. By R. M. Starbuck. 

This book represents the highest standard of plumbing work. It has been adopted and used 
as a reference book by the United States Government, in its sanitary work in Cuba, Porto 
Rico, and the Philippines, and by the principal Boards of Health of the United States and 
Canada. 

It gives connections, sizes and working data for all fixtures and groups of fixtures. It is 
helpful to the master plumber in demonstrating to his customers and in figuring work. It 
gives the mechanic and student quick and easy access to tiie best modern plumbing practice. 
Suggestions for estimating plumbing construction are contained in its pages. This book 
represents, in a word, the latest and best up-to-date practice, and should be in the hands of 
every architect, sanitary engineer and plumber who wishes to keep himself up to the minute 
on this important feature of construction. Contains following chapters, each illustrated 
with a full-page plate: Kitchen sink, laundry tubs, vegetable wash sink; lavatories, 
pantry sinks, contents of marble slabs; bath tub, foot and sitz bath, shower bath; water 
closets, venting of water closets; low-down water closets, water closets operated by flush 
valves, water closet range; slop sink, urinals, the bidet; hotel and restaurant sink, grease 
trap; refrigerators, safe wastes, laundry waste; lines of refrigerators, bar sinks, soda foun¬ 
tain sinks; horse stall, frost-proof water closets; connections for S traps, venting; con¬ 
nections for drum traps; soil pipe connections; supporting of soil pipe; main trap and 
fresh air inlet; floor drains and cellar drains, subsoil drainage; water closets and floor 
connections; local venting; connections for bath rooms; connections for bath rooms, con¬ 
tinued; connections for bath rooms, continued; connections for bath rooms, continued; 
examples of poor practice; roughing-work ready for test; testing of plumbing system; 
method of continuous venting; continuous venting for two-floor work; continuous venting 
for two lines of fixtures on three or more floors; continuous venting of water closets; plumb¬ 
ing for cottage house; construction for cellar piping; plumbing for residence, use of special 
fittings; plumbing for two-flat house; plumbing for apartment building; plumbing for 
double apartment building; plumbing for office building; plumbing for public toilet rooms; 
plumbing for public toilet rooms, continued; plumbing for bath establishment; plumbing 
for engine house, factory plumbing; automatic flushing for schools, factories, etc.; use of 
flushing valves; urinals for public toilet rooms; the Durham system, the destruction of 
pipes by electrolysis; construction of work without use of lead; Automatic sewage lift, 
automatic sump tank; country plumbing; construction of cesspools; septic tank and auto¬ 
matic sewage siphon; country plumbing; water supply for country house; thawing of 
water mains and service by electricity; double boilers; hot water supply of large build¬ 
ings ; automatic control of hot water tank; suggestions for estimating plumbing construc¬ 
tion. 400 octavo pages, fully illustrated by 55 full-page engravings. Price . $4.00 

STANDARD PRACTICAL PLUMBING. By R. M. Starbuck. 

A complete practical treatise of 450 pages covering the subject of Modern Plumbing 
in all its branches, a large amount of space being devoted to a very complete and practical 
treatment of the subject of Hot Water Supply and Circulation and Range Boiler Work. 
Its thirty chapters include about every phase of the subject one can think of, making it 


2 4 











CATALOGUE OF GOOD, PRACTICAL BOOKS 


an indispensable work to the master plumber, the journeyman plumber, and the apprentice 
plumber, containing chapters on: the plumber’s tools; wiping solder, composition and use; 
joint wiping; lead work; traps; siphonage of traps; venting; continuous venting; house 
sewer and sewer connections; house drain; soil piping, roughing; main trap and fresh air 
inlet; floor, yard, cellar drains, rain leaders, etc.; fixture wastes; water closets; ventilation; 
improved plumbing connections; residence plumbing; plumbing for hotels, schools, fac¬ 
tories, stables, etc.; modern country plumbing; filtration of sewage and water supply; 
hot and cold supply; range boilers; circulation; circulating pipes; range boiler problems; 
hot water for large buildings; water lift and its use; multiple connections for hot water 
boilers; heating of radiation by supply system; theory for the plumber; drawing for the 
plumber. Fully illustrated by 347 engravings. Price . , , .. $3.00 


RECEIPT BOOK 


HENLEY’S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO¬ 
CESSES. Edited by Gardner D. Hiscox. 

The most valuable Techno-chemical Receipt Book published, including over 10,000 selected 
scientific, chemical, technological, and practical receipts and processes. 

This is the most complete Book of Receipts ever published, giving thousands of receipts for 
the manufacturer of valuable articles for everyday use. Hints, Helps, Practical Ideas, and 
Secret Processes are revealed within its pages. It covers every branch of the useful arts and 
tells thousands of ways of making money and is just the book everyone should have at his 
command. 

Modern in its treatment of every subject that properly falls within its scope, the book may 
truthfully be said to present the very latest formulas to be found in the arts and industries 
and to retain those processes which long experience has proven worthy of a permanent record, 
To present here even a limited number of the subjects which find a place in this valuable 
work would be difficult. Suffice to say that in its pages will be found matter of intense in¬ 
terest and immeasurable practical value to the scientific amateur and to him who wishes to 
obtain a knowledge of the many processes used in the arts, trades and manufactures, a 
knowledge which will render his pursuits more instructive and remunerative. Serving as a 
reference book to the small and large manufacturer and suppplying intelligent seekers with 
the information necessary to conduct a process, the work will be found of inestimable worth 
to the Metallurgist, the Photographer, the Perfumer, the Painter, the Manufacturer of 
Glues, Pastes, Cements, and Mucilages, the Compounder of Alloys, the Cook, the Physician, 
the Druggist, the Electrician, the Brewer, the Engineer, the Foundryman, the Machinist, 
the Potter, the Tanner, the Confectioner, the Chiropodist, the Manicure, the Manufacturer 
of Chemical Novelties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, 
the Engraver, the Provisioner, the Glass 'Worker, the Goldbeater, the Watchmaker, the Jew¬ 
eler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairyman, the 
Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, the Veterinary 
Surgeon, and the Technologist in general. 

A mine of information, and up-to-date in every respect. A book which will prove of value, 
to EVERYONE, as it covers every branch of the Useful Arts. 800 pages. Price $3.00 

WHAT IS SAID OF THIS BOOK: 


“Your Twentieth Century Book of Receipts, Formulas and Processes duly received. I am 
glad to have a copy of it, and if I could not replace it money couldn’t buy it. It is the best 
thing of the sort I ever saw.” (Signed) M. E. Trux, 

SDarta, Wis. 

There are few persons who would not be able to find in the book some single formula that 
would repay several times the cost of the book.”— Merchant's Record and Show Window. 


RUBBER 


RUBBER HAND STAMPS AND THE MANIPULATION OF INDIA RUBBER. By 

T. O’Conor Sloane. 

This book gives full details on all points, treating in a concise and simple manner the elements 
of nearly everything it is necessary to understand for a commencement in any branch of the 
India Rubber Manufacture. The making of all kinds of Rubber Hand Stamps, Small Articles 
of India Rubber, U. S. Government Composition, Dating Hand Stamps, the Manipulation 
of Sheet Rubber, Toy Balloons. India Rubber Solutions, Cements, Blackings, Renovating 


25 












CATALOGUE OF GOOD, PRACTICAL BOOKS 


Varnish, and Treatment for India Rubber Shoes, etc.; the Hektograph Stamp Inks, am 
Miscellaneous Notes, with a Short Account of the Discovery, Collection, and Manufacture c 
India Rubber are set forth in a manner designed to be readily understood, the explanation 
being plain and simple. Including a chapter on Rubber Tire Making and Vulcanizing; also 
chapter on the uses of rubber in Surgery and Dentistry. Third revised and enlarged edition 
175 pages. Illustrated. $1.00 


SAWS 


SAW FILINGS AND MANAGEMENT OF SAWS. By Robert Grimshaw. 

A practical hand book on filing, gumming, swaging, hammering, and the brazing of band saws, 
the speed, work, and power to run circular saws, etc. A handy book for those who have charge 
of saws, or for those mechanics who do their own filing, as it deals with the proper shape and 
pitches of saw teeth of all kinds and gives many useful hints and rules for gumming, setting, 
and filing, and is a practical aid to those who use saws for any purpose. New edition, revised 
and enlarged. Illustrated. Price. $1.00 


STEAM ENGINEERING 


AMERICAN STATIONARY ENGINEERING. By W. E. Crane. 

This book begins at the boiler room and takes in the whole power plant. A plain talk on 
every-day work about engines, boilers, and their accessories. It is not intended to be scien¬ 
tific or mathematical. All formulas are in simple form so that any one understanding plain 
arithmetic can readily understand any of them. The author has made this the most prac¬ 
tical book in print; has given the results of his years of experience, and has included about 
all that has to do with an engine room or a power plant. You are not left to guess at a single 
point. You are shown clearly what to expect under the various conditions; how to secure 
the best results; ways of preventing “shut downs” and repairs; in short, all that goes to 
make up the requirements of a good engineer, capable of taking charge of a plant. It’s plain 
enough for practical men and yet of value to those high in the profession. 

A partial list of contents is: The boiler room, cleaning boilers, firing, feeding; pumps; 
inspection and repair; chimneys, sizes and cost; piping; mason work; foundations; testing 
cement; pile driving; engines, slow and high speed; valves; valve setting; Corliss engines, 
setting valves, single and double eccentric; air pumps and condensers; different types of 
condensers; water needed; lining up; pounds; pins not square in crosshead or crank; 
engineers’ tools; pistons and piston rings; bearing metal; hardened copper; drip pipes from 
cylinder jackets; belts, how made, care of; oils; greases; testing lubricants; rules and 
tables, including steam tables; areas of segments; squares and square root; cubes and cube 
root; areas and circumferences of circles. Notes on: Brick work; explosions; pumps; 
pump valves; heaters, economizers; safety valves; lap. lead, and clearance. Has a complete 
examination for a license, etc., etc. Second edition. 285 pages. Illustrated. Price . $2.00 

EMINENT ENGINEERS. By Dwight Goddard. 

Everyone who appreciates the effect of such great inventions as the Steam Engine, Steamboat, 
Locomotive, Sewing Machine, Steel Working, and other fundamental discoveries, is interested 
in knowing a little about the men who made them and their achievements. 

Mr. Goddard has selected thirty-two of the world’s engineers who have contributed most 
largely to the advancement of our civilization by mechanical means, giving only such facts as 
are of general interest and in a way which appeals to all, whether mechanics or not. 28C 
pages. 35 illustrations. Price.$1.50 

ENGINE RUNNER’S CATECHISM. By Robert Grimshaw. 

A practical treatise for the stationary engineer, telling how to erect, adjust and run the prin¬ 
cipal steam engines in use in the United States. Describing the principal features of various 
special and well-known makes of engines: Temper Cut-off, Shipping and Receiving Founda¬ 
tions, Erecting and Starting, Valve Setting, Care and Use, Emergencies, Erecting and Ad¬ 
justing Special Engines. 

The questions asked throughout the catechism are plain and to the point, and the answers 
are given in such simple language as to be readily understood by anyone. All the instructions 
given are complete and up-to-date; and they are written in a popular style, without any 
technicalities or mathematical formulae. The work is of a handy size for the pocket, clearly 
and well printed, nicely bound, and profusely illustrated. To young engineers this catechism 

26 












CATALOGUE OF GOOD, PRACTICAL BOOKS 


will be of great value, especially to those whu may be preparing to go forward to be examined 
for certificates of competency; and to engineers generally it will be of no little service, as they 
will find in this volume more really practical and useful information than is to be found any¬ 
where else within a like compass. 387 pages. Seventh edition. Price .... $2.00 

ENGINE TESTS AND BOILER EFFICIENCIES. By J. Buchetti. 

This work fully describes and illustrates the method of testing the power of steam engines, 
turbines and explosive motors. The properties of steam and the evaporative power of fuels. 
Combustion of fuel and chimney draft; with formulas explained or practically computed. 
255 pages, 179 illustrations...$3.00 

HORSEPOWER CHART. 

Shows the horsepower of any stationary engine without calculation. No matter what the 
cylinder diameter of stroke; -the steam pressure or cut off; the revolutions, or whether con¬ 
densing or non-condensing, it’s all there. Easy to use, accurate, and saves time and calcu¬ 
lations. Especially useful to engineers and designers. .50 cents 

MODERN STEAM ENGINEERING IN THEORY AND PRACTICE. By Gardner 
D. Hiscox. 

This is a complete and practical work issued for Stationary Engineers and firemen dealing 
with the care and management of boilers, engines, pumps, superheated steam, refrigerating 
machinery, dynamos, motors, elevators, air compressors, and all other branches with which 
the modern engineer must be familiar. Nearly 200 questions with their answers on steam 
and electrical engineering, likely to be asked by the Examining Board, are included. 

Among the chapters are: Historical; steam and its properties; appliances for the genera¬ 
tion of steam; types of boilers; chimney and its work; heat economy of the feed water; 
steam pumps and their work; incrustation and its work; steam above atmospheric pressure; 
flow of steam from nozzles; superheated steam and its work; adiabatic expansion of steam; 
indicator and its work; steam engine proportions; slide-valve engines and valve motion; 
Corliss engine and its valve gear; compound engine and its theory; triple and multiple 
expansion engine, steam turbine; refrigeration; elevators and their management; cost 
of power; steam engine troubles; electric power and electric plants. 487 pages. 405 en¬ 
gravings. Price.$3.00 

STEAM ENGINE CATECHISM. By Robert Grimshaw. 

This unique volume of 413 pages is not only a catechism on the question and answer princi¬ 
ple; but it contains formulas and worked-oin answers for all the Steam problems that apper¬ 
tain to the operation and management of the Steam Engine. Illustrations of various valves 
and valve gear with their principles of operation are given. Thirty-four Tables that are 
indispensable to every engineer and fireman that wishes to be progressive and is ambitious to 
become master of his calling are within its pages. It is a most valuable instructor in the 
service of Steam Engineering. Leading engineers have recommended it as a valuable educa¬ 
tor for the beginner as well as a reference book for the engineer. It is thoroughly indexed 
for every detail. Every essential question on the Steam Engine with its answer is contained 
in this valuable work. Sixteenth edition. Price.$2.00 

STEAM ENGINEER’S ARITHMETIC. By Colvin-Cheney. 

A practical pocket book for the steam engineer. Shows how to work the problems of the 
engine room and shows “why.” Tells how to figure horse-power of engines and boilers; area 
of boilers; has tables of areas and circumferences; steam tables; has a dictionary of engineering 
terms. Puts you on to all all of the little kinks in figuring whatever there is to figure around 
a power plant. Tells you about the heat unit; absolute zero; adiabatic expansion; duty ol 
engines; factor of safety; and 1,001 other things; and everything is plain and simple—not 
the hardest way to figure, but the easiest. 2nd Edition.50 cents 


STEAM HEATING AND VENTILATION 


PRACTICAL STEAM, HOT-WATER HEATING AND VENTILATION. By A. G. 

King. 

This book is the standard and latest work published on the subject and has been prepared for 
the use of all engaged in the business of steam, hot water heating, and ventilation. It is an 
original and exhaustive work. Tells how to get heating contracts, how to install heating and 
ventilating apparatus, the best business methods to be used, with “Tricks of the Trade” for 


27 











CATALOGUE OF GOOD, PRACTICAL BOOKS 


shop use. Rules and data for estimating radiation and cost and such tables and information 
as make it an indispensable work for everyone interested in steam, hot water heating, and venti¬ 
lation. It describes all the principal systems of steam, hot water, vacuum, vapor, and vacuum- 
vapor heating, together with the new accelerated systems of hot water circulation, including 
chapters on up-to-date methods of ventilation and the fan or blower system of heating and 
ventilation. Containing chapters on: I. Introduction. II. Heat. III. Evolution of 
artificial heating apparatus. IV. Boiler surface and settings. V. The chimney flue. VI. 
Pipe and fittings. VII. Valves, various kinds. VIII. Forms of radiating surfaces. IX. 
Locating of radiating surfaces. X. Estimating radiation. XI. Steam-heating apparatus. 
XII. Exhaust-steam heating. XIII. Hot-water heating. XIV. Pressure systems of hot- 
water work. XV. Hot-water appliances. XVI. Greenhouse heating. XVII. Vacuum 
^apor and vacuum exhaust heating. XVIII. Miscellaneous heating. XIX. Radiator and 
pipe connections. XX. Ventilation. XXI. Mechanical ventilation and hot-blast heating. 
XXII. Steam appliances. XXIII. District heating. XXIV. Pipe and boiler covering. 
XXV. Temperature regulation and heat control. XXVI. Business methods. XXVII. 
Miscellaneous. XXVIII. Rules, tables and useful information. 367 pages. 300 detailed 
engravings. Price. $3.00 


STEAM PIPES 


STEAM PIPES: THEIR DESIGN AND CONSTRUCTION. By Wm. H. Booth. 

The work is well illustrated in regard to pipe joints, expansion offsets, flexible joints, and 
self-contained sliding joints for taking up the expansion of long pipes. In fact, the chapters 
on the flow of steam and expansion of pipes are most valuable to all steam fitters and users. 
The pressure strength of pipes and method of hanging them are well treated and illustrated. 
Valves and by-passes are fully illustrated and described, as are also flange joints and their 
proper proportions, exhaust heads arid separators. One of the most valuable chapters is that 
on superheated steam and the saving of steam by insulation with the various kinds of felt¬ 
ing and other materials with comparison tables of the loss of heat in thermal units from naked 
and felted steam pipes. Contains 187 pages. Price. $2.00 


STEEL 


AMERICAN STEEL WORKER. By E. R. Markham. 

This book tells how to select, and how to work, temper, harden, and anneal steel for everything 
on earth. It doesn’t tell how to temper one class of tools and then leave the treatment of 
another kind of tool to your imagination and judgment, but it gives careful instructions for 
every detail of every tool, whether it be a tap, a reamer or just a screw-driver. It tells about 
the tempering of small watch springs, the hardening of cutlery, and the annealing of dies. In 
fact there isn’t a thing that a steel worker would want to know that isn’t included. It is the 
standard book on selecting, hardening, and tempering all grades of steel. Among the 
chapter headings might be mentioned the following subjects: Introduction; the workman; 
steel; methods of heating; heating tool steel; forging; annealing; hardening baths; baths 
for hardening; hardening steel; drawing the temper after hardening; examples of hard¬ 
ening; pack hardening; case hardening; spring tempering; making tools of machine steel; 
special steels; steel for various tools; causes of trouble; high speed steels, etc. 366 pages. 
Very fully illustrated. 3rd Edition. Price. $2.50 

HARDENING, TEMPERING, ANNEALING, AND FORGING OF STEEL. By J. V. 

Woodworth. 

A new work treating in a clear, concise manner all modern processes for the heating, annealing 
forging, welding, hardening, and tempering of steel, making it a book of great practical value 
to the metal-working mechanic in general, with special directions for the successful hardening 
and tempering of all steel tools used in the arts, including milling cutters, taps, thread dies, 
reamers, both solid and shell, hollow mills, punches and dies, and all kinds of sheet metal 
working tools, shear blades, saws, fine cutlery, and metal cutting tools of all description, as 
well as for all implements of steel both large and small. In this work the simplest and most 
satisfactory hardening and tempering processes are given. 

The uses to which the leading brands of steel may be adapted are concisely presented, and their 
treatment for working under different conditions explained, also the special methods for the 
hardening and tempering of special brands. 

A chapter devoted to the different processes for Case-hardening is also included, and special 
reference made to the adoption of machinery steel for tools of various kinds. 4th Edition. 288 
pages. 201 Illustrations. Price. $2.50 


28 












CATALOGUE OF GOOD, PRACTICAL BOOKS 


TURBINES 


MARINE STEAM TURBINES. By Dr. G. Bauer and 0 . Lasche. Assisted by 
E. Ludwig and H. Vogel. Translated from the German and edited by M. G. S. 
Swallow. 

This work forms a supplementary volume to the book entitled “ Marine Engines and Boilers.” 
The authors of this book, Dr. G. Bauer and O. Lasche, may be regarded as the leading 
authorities on turbine construction. 

The book is essentially practical and discusses turbines in which the full expansion of steam 
passes through a number of separate turbines arranged for driving two or more shafts, as 
in the Parsons system, and turbines in which the complete expansion of steam from inlet 
to e*haust pressure occurs in a turbine on one shaft, as in the case of the Curtis machines. 
It will enable a designer to carry out all the ordinary calculations necessary for the con¬ 
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theoretical works. 

Numerous tables, curves and diagrams will be found, which explain with remarkable lucidity 
the reason why turbine blades are designed as they are, the course which steam takes through 
turbines of various types, the thermodynamics of steam turbine calculation, the influence 
of vacuum on steam consumption of steam turbines, etc. In a word, the very information 
which a designer and builder of steam turbines most requires. The book is divided into 
parts as follows: 1. Introduction. 2. General remarks on the design of a turbine installa¬ 
tion. 3. The calculation of steam turbines. 4. Turbine design. 5. Shafting and pro¬ 
pellers. 6. Condensing plant. 7. Arrangement of turbines. 8. General remarks on the 
arrangement of steam turbines in steamers. 9. Turbine-driven auxiliaries. 10. Tables. 
Large octavo. 214 pages. Fully illustrated and containing 18 tables. Including an entropy 
chart. Price, net.$3.50 


WATCH MAKING 


WATCHMAKER’S HANDBOOK. By Claudius Saunier. 

This famous work has now reached its seventh edition and there is no work issued that can 
compare to it for clearness and completeness. It contains 498 pages and is intended as a 
workshop companion for those engaged in Watch-making and allied Mechanical Arts. Nearly 
250 engravings and fourteen plates are included. Price ... .... $3.00 


29 









JUST PUBLISHED! 


QUESTIONS AND ANSWERS 

RELATING TO MODERN 

AUTOMOBILE DESIGN, CONSTRUCTION AND REPAIR 

By VICTOR W. PAGE, M. E., 

Author of “The Modern Gasoline Automobile”, “The Modern Gas Tractor", Etc., Etc. 

600 (6x9) Pages. 350 Illustration*, 

PRICE $1.50. 


T HIS practical treatise consists of a series of thirty-six 
lessons, covering with nearly 2000 questions and their 
answers—the automobile, its construction, operation and 
repair. The subject matter is absolutely correct and explained 
in simple language. If you can’t answer all of the following 
questions, you need this work. The answers to these and 
nearly 2000 more are to be found in its pages. 

Give the name of all important parts of an automobile 
and describe their functions. Describe action of latest 
types of kerosene carburetors. What is the difference 
between a “Double” ignition system and a “dual” ignition 
system? Name parts of an induction coil? How are valves 
t.imed? What is an electric motor starter and how does it 
work? What are advantages of worm drive gearing? 
Name all important types of ball and roller bearings? What is a “Three- 
quarter” floating axle*? What is a two-speed axle? What is the Vulcan electric 
gearshift? Name the causes of lost power in automobiles. Describe all noises 
due to deranged mechanism and give causes? How can you adjust a carburetor 
by the color of the exhaust gases? W 7 hat causes “popping” in the carburetor? 
What tools and supplies are needed to equip a car? How do you drive various 
makes of cars? What is a differential lock and where is it used? Name different 
systems of wire wheel construction, etc., etc 



A popular work at a popular price. Answers every question you 
may ask relating to the modern automobile. 


Copies of this book sent prepaid to any address on receipt of price. 

THE NORMAN W. HENLEY PUBLISHING C0 M 

132 NASSAU STREET, 


NEW’ YORK 






















JUST PUBLISHED! 


How to Rim and Repair an Attto f 


THE MODERN GASOLINE 

AUTOMOBILE 

Its Construction, Operation, Maintenance 

and Repair . 

By VICTOR W. PAG£, M. E. 

500 Illustrations — Over 700 (6 x 9) Pages — Ten Large Folding Plates 

PRICE $2.50 



A COMPLETE AUTOMOBILE BOOK, SHOWING EVERY RECENT IMPROVEMENT. 

By a careful study of the pages of this book one can gain practical knowledge of 
the automobile that will save time, money and worry. The book tells you just what 
to do, how and when to do it. Nothing has been omitted, no detail has been slighted 
Every part of the automobile, its equipment, accessories, tools, supplies, spare parts 
necessary, etc, have been discussed comprehensively. If you are or intend to become 
a motorist, or are in any way interested in the modern Gasoline Automobile, this is.a 
book you cannot afford to be without 

COVERS EVERY PHASE OF 1913 AUTOMOBILE PRACTICE AND IS SUPERIOR 
TO ANY TREATISE HERETOFORE PUBLISHED. 

Written in simple language by a recognized authority, familiar with every branch of the auto¬ 
mobile industry. Free from technical terms. Everything is explained so simply that anyone of 
average intelligence may gain a comprehensive knowledge of the gasoline automobile. The informa¬ 
tion is up to date and includes, in addition to an exposition of principles of construction and description 
of all types of automobiles and their parts, valuable money-saving hints on the care and operation of 
motor cars propelled by internal combustion engines. 

Motorists, students, salesmen, demonstrators, repairmen, chauffeurs, garage owners, and even 
designers or engineers need this work because it is complete, authoritative and thoroughly up-to-date. 
Other works dealing with automobile construction published in the past, make no reference to modern Improve* 
ments becaose of their recent development. All are fully discussed and illustrated in this volume. 

CONTAINS SPECIAL CHAPTERS ON 


I. Types of Modern Automobiles. II. How Power ^Generated. III. Principal Parts of Gasoline Engines, Their Design, 
Construction, and Application. IV. Constructional Details of Pistons. V. Liquid Fuels Used and Methods 
of Vai lorizing to Obtain Explosive Gas. VI. Automobile Power-Plant Ignition Systems Outlined. 

VII. Reasons for Lubrication of Mechanism. VIII. Utility of Clutches and 'Gearsets. 

IX. The Chassis and Its Parts. X. Wheels, Rims and Tires. XI. Motor Car Equip¬ 
ment and Accessories. XII. Operating Advice and Explanation of Automobile 
Control Methods. XIII. Hints to Assist in Locating Power-Plant 
Troubles. XIV. Keeping Up the Motor-Car Chassis. 


Copies of this book sent prepaid to any address on receipt of price. 

THE NORMAN W. HENLEY PUBLISHING CO.. 

132 NASSAU STREET. • NEW YORK. 

















GASOLINE ENGINE TROUBLE CHART 


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JUST PUBLISHED 


THE MODERN 

GAS TRACTOR 

By VICTOR W PAGE, M. E. 

Author of “The Modern Gasoline Automobile/’ Etc. 

A COMPLETE TREATISE DESCRIBING ALL TYPES AND SIZES OF GASOLINE, 
KEROSENE AND OIL TRACTORS. CONSIDERS DESIGN AND CONSTRUCTION 
EXHAUSTIVELY, GIVES COMPLETE INSTRUCTIONS FOR CARE, OPERATION 
AND REPAIR, OUTLINES ALL PRACTICAL APPLICATIONS ON THE ROAD 
AND IN THE FIELD. THE BEST AND LATEST WORK ON FARM TRACTORS 
AND TRACTOR POWER PLANTS. 

480 PAGES-THREE FOLDING PLATES-204 ILLUSTRATIONS 

PRICE - - $2.00 

A modern exposition in the language of the field showing and describing 
every recent improvement in tractors and auxiliary appliances. All money 
making farms use power. Learn how to apply it now. 

This work ia written by a recognized authority on self-propelled vehicles and internal combustion 
motors. Everything is explained so simply that anyone of average intelligence may obtain a compre- 
hensive knowledge of gas tractor operation, maintenance and repair. Tells how they are constructed 
and explains fully the reasons for varying designs. Contains special chapters on driving the tractor on 
field and road, what to expect from tractors in various kinds of work, cost of operation and money* 
making hints on repairs. It describes all ignition systems, all types of gasoline and kerosene vapori* 
zers and carburetors, latest forms of power plants and installation, clutches, speed changing and revers¬ 
ing gears and all frame parts and their functions. Tells how to tell brake horsepower from draw bar 
or horse equivalent power, how to make adjustments to power plants, change speed gearing and other 
parts. Describes tools for tractor repair and gives plans for tractor sheds so they can be used in winter 
for stationary power or workshops where all repairs may be made. Outlines control systems of leading 
types and shows, simple hitches for working various implements in combination. Describes fully trac¬ 
tors for small farms and orchards as well as types of the largest capacity. All illustrations are plainly 
marked with all important parts indicated so they may be easily identified- Drawings are simple bat 
in correct proportion. Every illustration has been specially made for this book. 

ALL FARMERS, STUDENTS, BLACKSMITHS, MECHANICS, SALESMEN, IM- 
PLEMENT DEALERS, DESIGNERS AND ENGINEERS NEED THIS WORK 

Written in language understood by alL No technical terms. 

COVERS EVERY PHASE OF 1914 TRACTOR ENGINEERING PRACTICE AND 
IS SUPERIOR TO ANY TREATISE HERETOFORE PUBLISHED 



Copies of this book sent prepaid to any address on receipt of price. 


THE NORMAN W. HENLEY PUBLISHING CO M 

132 NASSAU STREET, * - NEW YORK. 



















JUST PUBLISHED ! 





MOTORCYCLES, SIDE CARS 
AND CYCLECARS 

Their Construction, Management and Repair 
By VICTOR W. PAGE, M. E, 

Author of “The Modern Gasoline Automobile,’’ Etc., Etc. 

Contains over 350 specially made illustrations showing the most 
valuable series of drawings pertaining to motorcycle 
design and construction ever published. 


550 Pages PRICE $1.50 5 Folding Plates 


The only complete work published for the Motorcyclist and Cyclecarist. Describes fully 
all leading types of Machines, their Design, Construction, Maintenance, Operation and Repair. 

This treatise traces the motorcycle from its earliest forms to the approved models of 
the present day. It outlines fully the operation of two and four cycle power plants and 
all ignition, carburetion and lubrication systems in detail. Describes all representative 
types of free engine clutches, variable speed gears and power transmission systems. 
Gives complete instructions for operating and repairing all types. Considers fully elec¬ 
tric self-starting and lighting systems, all types of spring frames and spring forks and 
shows leading control methods. 


The prospective purchaser and novice rider will find the descriptions of 
various engines and auxiliary systems easy to understand; the repair hints, 
suggestions for locating troubles and operating instructions invaluable. 

The Dealer, Mechanic and Expert Rider will find this treatise a work of 
reference without an equal. 

For those desiring technical information a complete series of tables and many form¬ 
ulae to assist in designing are included. The work tells how to figure power needed to 
climb grades, overcome air resistance and attain high speeds. It shows how to select 
gear ratios for various weights and powers, how to figure braking efficiency required, 
gives sizes of belts and chains to transmit power safely and shows how to design sprock¬ 
ets, belt pulleys, etc. This work also includes complete formulae for figuring horse¬ 
power, shows how dynamometer tests are made, defines relative efficiency of air and 
water cooled engines, plain and anti-friction bearings and much other data of a practi¬ 
cal. helpful engineering nature. Remember that you get this information in addition 
to the practical description and instructions which alone are worth several times the 
price of the book. 


THE CHAPTERS ON CYCLECARS GIVE ALL THE INFORMATION NEEDED 
TO UNDERSTAND THE CONSTRUCTION AND OPERATION OF 
THIS LATEST DEVELOPMENT IN THE FIELD 
OF SELF-PROPELLED VEHICLES. 


Copies of this book sent prepaid on receipt of price. 

THE NORMAN W. HENLEY PUBLISHING CO 

132 Nassau St., New York 


















“SHOP^ KINKS,” 

ROBERT GRIMSHAW. 


400 PAGES. 222 ILLUSTRATIONS. 

Price, $2.50. 

This book is entirely different from any other on machine shop practice. It 
is not descriptive of universal or common shop usage, but shows special ways of 
doing work better, more cheaply and more rapidly than usual , as done in fifty 
or more leading shops in Europe and America. 

Some of its over 500 Items , and 222 Illustrations, are contributed directly for 
its pages by eminent constructors ; the rest have been gathered by the author i® 
his Thirty Years' Travel and Experience. 

It is the most useful book yet issued for the Machinist. 

No shop can afford to be without it. 

Every employee can fit himself for advancement by studying its paget. 

It will benefit all, from apprentice to proprietor. 


A FEW OF THE MANY TESTIMONIALS OF “ SHOP KINKS.” 

This is an interesting written book, with plenty of good engravings, which are 
a great help in making clear any text, no matter how well written. There are over 
five hundred separate items, selected from the author's observations and the ob¬ 
servations of others, as well as from the leading mechanical papers. It abounds in 
handy ways of doing work, commonly called shop kinks, as the title of the book 
implies, and there is enough useful information in the book to repay the outlay 
many times over. The devices shown are all taken from actual practice and the 
name of the shops where they are to be found is given, so there is nothing that can 
be called untried or impracticable in It. The information imparted by books of 
this class, especially when written by men of long experience, is the most valuable 
that can be obtained, and the intelligent shopman will carefully consider the means 
employed in various shops, determine which is best adapted to his particular case, 
and adopt the method that will save the most time and money for their employer. 
No machinist can read it without finding new methods and ideas which will be of 
value to him —Machinery, March, 1896. 

“ A strongly bound cloth book, 400 pages, entitled “ Shop Kinks ” by that 
living encyclopaedia of mechanics, Robert Grimshaw. As might be expected, the 
author covers almost every possible subject that could come up in a machine shop. 
The articles are well illustrated, and the different processes clearly explained. 
B5r. Grimshaw i» not one of those who think there is nothing known outside of 
himself, but is ever gleaning “ Kinks ” from other men’s brains. A copy should be 
on the desk of every machinist in a factory repair shop, for the right “Kink ” at the 
right time will often prevent the stoppage of a factory.”— Wade's Fibre and Fabric , 
Feb. 15, 1896. _ 

NORMAN W. HENLEY & CO PUBLISHERS, 

132 Nassau Street, New York. 


Special circular describing the above sent on request , or we will tend copies 

on receipt of the price. 






JTTJST JPUBJjIS 


MECHANICAL 


OVEMENTS, 


POWERS, DEVICES, AND APPLIANCES^ 

By GARDNER D. HISCOX, n.E., 

Author of “Gas, Gasoline, and Oil Engines.* 

Svo* Over 400 Pages. 1649 Illustrations, with Descriptive Text, 

PRICE $3.00. 

A dictionary of Mechanical Movements, Powers, Devices, and Appliances, with 
1649 illustrations and explanatory text. This is a new work on illustrated mechanics, 
mechanical movements, de.'ices, and appliances, coveriner nearly the whole range 
of the practical and inventive field, for the use of Mechanics, Inventors, Engineers, 
Draughtsmen, and all persons interested in mechanical contrivances. 

SECTIONS. 

Section I. Mechanical Powers.— Weights, Revolution of Forces, Pressures, 
Levers, Pulleys, Tackle, etc. 

Section II. Transmission of Power.—Ropes, Belts, Friction Gear, Spur 

Bevel, and Screw Gear, etc. 

Section III. Measurement of Power.— Speed, Pressure, Weight, Numbers, 

Quantities, and Appliances. 

Section IV. Steam Power- Boilers and Adjuncts.—Engines, Valves and 

Valve Gear, Parallel Motion Gear, Governors and Engine Devices, Rotary En¬ 
gines, Oscillating Engines. 

Section V. Steam Appliances.— Injectors, Steam Pumns, Condensers, Sepa¬ 
rators, Traps, and Valves 

Section VI. Motive Power-Gas and Gasoline Engines.—Valve Gear 

and Appliances, Connecting Rods and Heads. 

Section VII. Hydraulic Power and Devices.— Water Wheels, Turbines. 
Governors, Impact Wheels, Pumps, Rotary Pumps, Siphons, Water Lifts, Eject¬ 
ors, Water Rams, Meters, Indicators, Pressure Regulators, Valves, Pipe Joints, 
Filters, etc. 

Section VIII. Air Power Appliances.— Wind Mills, Bellows, Blowers, Air 
Compressors, Compressed Air Tools, Motors, Air Water Lifts, Blow Pipes, etc. 

Section IX. Electric Power and Construction.— Generators, Motors, Wir¬ 
ing, Controlling and Measuring, Lighting, Electric Furnaces, Fans, Search Light 
and Electric Appliances. 

Section X. Navigation and Roads.— Vessels, Sails, Rope Knots, Paddle 
Wheels, Propellers, Road Scraper and Roller, Vehicles, Motor Carriages, Tricy¬ 
cles, Bicycles, and Motor Adjuncts. 

Section XI. Gearing.— Racks and Pinions, Spiral, Elliptical, and Worm Gear, 
Differential and Stop-Motion Gear, Epicyclical and Planetary Trains, “Fer¬ 
guson’s ” Paradox. 

Section XII. Motion and Devices Controlling Motion.— Ratchets and 
Pawls, Cams, Cranks, Intermittent and Stop Motions, Wipers, Volute Cams, 
Variable Cranks, Universal Shaft Couplings, Gyroscope, etc. 

Section XIII. Horological.— Clock and Watch Movements and Devices. 

Section XIV. Mining.— Quarrying. Ventilation, Hoisting, Conveying, Pulver 
izing. Separating, Roasting, Excavating, and Dredging. 

Section XV. Mill and Factory Appliances.— Hangers, Shaft Bearings, Ball 

Bearings, Steps, Couplings, Universal and Flexible Couplings, Clutches, Speed 
Gears, Shop Tools, Screw Threads, Hoists, Machines. Textile Appliances, etc. 

Section XVI, Construction and Devices.— Mixing, Testing, Stump and Pile 
Pulling, Tackle Hooks, Pile Driving, Dumping Cars, Stone Grips, Derricks, Con¬ 
veyor, Timber Splicing, Roof and Bridge Trusses, Suspension Bridges. 

Section XVII. Draughting Devices.— Parallel Rules, Curve Delineators, 

Trammels, Ellipsographs, Pantographs, etc. 

Section XVIII. Miscellaneous Devices.—Animal Power, Sheep Shears, 
Movements and Devices. Elevators, Cranes, Sewing, Typewriting and Printing 
Machines, Railway Devices, Trucks, Brakes, Turntables, Locomotives, Gas, Gas 
Furnaces, Acetylene Generators, Gasoline Mantle Lamps, Fire Arms, etc. 

*** Prepaid to any address on receipt of price 

NORMAN W.HENLEY&CO., PubUhers 

132 NASSAU STREET, NEW YORK. 




A Complete Electrical Library 

By Prof. T. O’CONOR SLOANE. 

(HE BEST ELECTRICAL BOOKS. EACH ONE SOLD SEPARATELY. 


How to Become a Successful Electrician I 

Illustrated. $1.00. 

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Standard Electrical Dictionary. 

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—Electrical Engineer. 

A special circular, fully describing the above, also our catalogues of dooks for 
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trades, sent free to any address, on request. 

NORMAN W. HENLEY & CO., Publishers, 

132 NASSAU STREET, NEW YORK. 

















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